This is the ONLY Chocolate Slab Cake and Fudge Frosting recipe you need! Whether you keep it simple or go all out with decorations, this Chocolate Fudge Frosted Slab Cake will become your go-to recipe. The chocolate cake has a tender soft crumb which pairs beautifully with the thick chocolate fudge frosting.
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Ingredients For This Recipe
Chocolate Slab Cake
- All-Purpose Flour: The foundation of our chocolate slab cake, providing structure and softness.
- White Sugar: Sweetens the cake and helps in achieving a tender crumb.
- Brown Sugar: Adds a hint of caramel-like flavor and extra moisture.
- Cocoa Powder: The star ingredient, cocoa powder gives that deep, rich chocolate taste.
- Instant Coffee Granules: A secret touch to intensify the chocolate flavor, entirely optional.
- Baking Soda & Baking Powder: These leavening agents ensure our cake rises to fluffy perfection.
- Salt: A pinch of salt balances the sweetness and enhances overall flavor.
- Milk: Adds moisture and helps to create a smooth batter.
- Vegetable Oil: For moisture and a tender texture.
- Vanilla Extract: A dash of vanilla adds a warm, aromatic flavor.
- Eggs: Bind the ingredients together and contribute to the cake's structure.
- Hot Water: Helps to "bloom" the cocoa, bringing out a richer chocolate flavor.
Chocolate Fudge Frosting
- Dark or Milk Chocolate: Choose based on your preference for a richer or milder chocolate taste.
- Unsalted Butter: Adds creaminess and sets the texture of the frosting.
- Powdered Sugar: For added sweetness and smoothness.
- Vanilla Extract: Complements the chocolate flavor.
- Instant Coffee Granules: Like in the cake, it deepens the chocolate flavor in the frosting.
- Salt: Just a pinch to balance the flavors.
- Cream: Creates a luxurious, velvety texture in the frosting.
How To Make Chocolate Slab Cake
Chocolate Cake:
Preheat Oven and Prepare Pan: Preheat your oven. Grease and line a 9 x 13-inch baking pan with parchment paper. This ensures easy removal of the cake once it's baked.
Sift Dry Ingredients: Sift together the all-purpose flour, cocoa powder, baking soda, baking powder, and salt. Sifting prevents lumps and helps to combine the ingredients evenly.
Add Sugars and Coffee Granules: To the sifted ingredients, add both white and brown sugars, and the instant coffee granules (if using). Whisk them together thoroughly. This ensures an even distribution of sweetness and flavor throughout the cake.
Combine Wet Ingredients: In a separate bowl, whisk together milk, vegetable oil, vanilla extract, and eggs until well combined.
Mix Wet into Dry Ingredients: Create a well in the center of the dry ingredients and pour the wet mixture into it. Gently fold them together until just combined. Be cautious not to overmix, as this can affect the cake's texture.
Add Hot Water: Gradually mix in the hot water. The batter will be quite thin, but this is expected. The hot water helps to enhance the cocoa flavor, leading to a rich chocolate taste.
Bake the Cake: Pour the batter evenly into the prepared pan. Bake in the preheated oven for about 40-45 minutes, or until a toothpick inserted into the center comes out clean.
Cool the Cake: Let the chocolate slab cake cool in the pan for about 20 minutes, then transfer it to a wire rack to cool completely.
Chocolate Fudge Frosting
Melt Ingredients: In a medium saucepan over medium heat, combine chocolate, unsalted butter, powdered sugar (if using), vanilla extract, instant coffee granules (if using), a pinch of salt, and cream. Stir continuously until the chocolate and butter melt and the mixture becomes smooth.
Cool and Thicken Frosting: Once the frosting is smooth, remove the pan from the heat. Transfer the frosting to a mixing bowl and let it cool to room temperature. Refrigerate the frosting until it thickens to a spreadable consistency.
Frost the Cake: When the chocolate slab cake is completely cool and the frosting is of the right consistency, spread the frosting over the cake using an angled spatula.
Decorate (Optional): Decorate your chocolate slab cake with chocolate shavings, sprinkles, or any other decoration of your choice.
Fay's Top Tips
Important Tip for the Cake Recipe: When combining the wet and dry ingredients, make sure not to overmix the batter. Overmixing can result in a dense cake instead of a light and fluffy one. Stir just until everything is combined, even if there are a few small lumps. The hot water will help smooth out the batter, and any lumps will dissolve during baking.
Important Tip for the Frosting Recipe: Let the frosting cool to room temperature before putting it in the fridge to thicken. This helps achieve the right consistency for spreading. If you refrigerate the frosting while it's still warm, it might become too thick or grainy. Cooling it first ensures a smooth, creamy texture that's easy to spread on the cake.
Recipe Variations
Cake Variations:
Chocolate Orange Cake: Add the zest of one orange and 1 teaspoon of orange extract to the wet ingredients. You can also substitute some of the milk with freshly squeezed orange juice for a zesty twist.
Chocolate Raspberry Cake: Mix in 1 cup of fresh raspberries into the cake batter before baking. You can also add a layer of raspberry jam between the cake layers for an extra burst of fruit flavor.
Mocha Cake: Increase the instant coffee granules to 1 tablespoon and add ½ teaspoon of espresso powder to the dry ingredients. This will intensify the coffee flavor and create a mocha cake.
Chocolate Coconut Cake: Replace ¼ cup of flour with ¼ cup of shredded coconut. Add 1 teaspoon of coconut extract to the wet ingredients. You can also sprinkle toasted coconut on top of the frosting.
Peanut Butter Chocolate Cake: Swirl ½ cup of peanut butter into the cake batter before baking. For the frosting, mix in ¼ cup of creamy peanut butter for a rich, nutty flavor.
Frosting Variations:
Salted Caramel Chocolate Frosting: Add ¼ cup of caramel sauce and a pinch of sea salt to the frosting. This will create a delicious salted caramel chocolate flavor.
Mint Chocolate Frosting: Add 1 teaspoon of peppermint extract to the frosting. You can also add a few drops of green food coloring for a minty look.
Hazelnut Chocolate Frosting: Mix in ¼ cup of Nutella or another hazelnut spread into the frosting for a rich, nutty flavor.
Spicy Chocolate Frosting: Add ½ teaspoon of ground cinnamon and a pinch of cayenne pepper to the frosting. This will give your cake a warm, spicy kick.
Espresso Chocolate Frosting: Dissolve 1 tablespoon of instant espresso powder in the cream before adding it to the frosting. This will enhance the chocolate flavor with a rich coffee taste.
Feel free to mix and match these variations to create your own unique version of this chocolate cake!
More Cakes You Might Like
If you're in the mood for more easy homemade cakes, here are a few you'll love trying next:
- Chocolate Sheet Cake - A soft, fluffy chocolate cake topped with a simple fudge-style frosting.
- Eggless Carrot Cake (Crazy Cake Style) - Made with no eggs, butter, or milk but still packed with warm spice and smooth cream cheese frosting.
- Chocolate Chip Cookie Cake - A rich, chewy cookie-style cake that's baked in one pan and perfect for sharing.
- Moist Carrot Cake with Cream Cheese Frosting
- Dairy Free Chocolate Cake
- Vegan Lemon Cake
- Eggless Chocolate Lava Cake
Frequently Asked Questions
Yes, you can substitute all-purpose flour with cake flour for a lighter texture, or use a gluten-free flour blend if you need a gluten-free option. Just keep in mind that different flours may alter the texture and flavor slightly. If using a gluten-free blend, make sure it includes a binding agent like xanthan gum.
Yes, you can omit the coffee granules if you prefer. They enhance the chocolate flavor without making the cake taste like coffee, but they aren't essential. You can also substitute them with decaffeinated coffee granules if caffeine is a concern.
Yes, you can make the frosting ahead of time. Store it in an airtight container in the refrigerator for up to 3 days. When you're ready to use it, let it come to room temperature and give it a good stir. If it's too thick, you can add a splash of cream to reach the desired consistency.
Definitely! You can add chocolate chips, nuts, or fruit to the cake batter. For the frosting, consider mixing in crushed cookies, candy pieces, or flavor extracts like almond or coconut. Just be mindful of the additional moisture or fat content, which can alter the final texture.
Chocolate Slab Cake with Chocolate Fudge Frosting
INGREDIENTS
Chocolate Cake
- 1¾ cup all-purpose flour
- 1½ cups white sugar
- ½ cup brown sugar
- ¾ cup cocoa powder
- 1 teaspoon instant coffee granules
- 2¼ teaspoon baking soda
- ½ teaspoon baking powder
- ½ teaspoon salt
- 1 cup milk
- ½ cup vegetable oil or light olive oil
- 2 teaspoon vanilla extract
- 2 eggs large
- 1 cup water hot
Chocolate Fudge Frosting
- 350 g (12½ oz) dark chocolate
- 130 g (9 tablespoon) butter unsalted
- 100 g (3½ oz) powdered sugar
- 2 teaspoon vanilla extract
- ½ teaspoon instant coffee granules
- 1 pinch salt
- 200 ml (¾ cup) heavy cream
INSTRUCTIONS
Chocolate Cake
- Preheat your oven to 350°F (175°C). Grease and line a 9 x 13 pan with parchment paper.
- In a large mixing bowl, sift together the all-purpose flour, cocoa powder, baking soda, baking powder, and salt using a mesh strainer. Sifting helps to ensure that the dry ingredients are well combined and free of lumps.
- Add brown sugar, white sugar and coffee granules to dry ingredients. Use a hand whisk to thoroughly combine all of the dry ingredients. This helps to evenly distribute the leavening agents and sugar, ensuring a uniform texture in your cake.
- In a separate bowl, whisk together the milk, vegetable oil, vanilla extract, and eggs. Ensure that the wet ingredients are well combined.
- Create a well in the centre of the dry ingredients. Pour the wet ingredients into the well. Gently fold the dry ingredients into the wet ingredients until just combined.
- Gradually add the hot water to the batter, stirring continuously. The batter will be thin, but this is normal. The hot water helps to bloom the cocoa and create a moist cake.
- Continue to mix the batter until it becomes smooth. The consistency should be thin but well-mixed.
- Pour the batter evenly into the prepared cake pan. Tap the pan on the counter to release any air bubbles.
- Place the pan in the preheated oven and bake for 40-45 minutes or until a toothpick inserted into the centre comes out clean.
- Allow the cake to cool in the pan for 20 minutes before transferring it to a wire rack to cool completely.
- Once the cakes are completely cool, you can frost them with your favorite frosting or serve them as-is.
Chocolate Fudge Frosting
- In a medium-sized pan over medium heat, combine the chopped chocolate, unsalted butter, powdered sugar (if using), vanilla, instant coffee granules (if using), cream and a pinch of salt.
- Stir the ingredients continuously with a wooden spoon or silicone spatula until the chocolate and butter are completely melted and the mixture is smooth. The sugar, if used, should dissolve into the mixture.
- Mix until the mixture is well combined and has a glossy texture.
- Once the mixture is smooth and well combined, remove the pan from the heat.
- Transfer the frosting to a mixing bowl. Let it come to room temperature then refrigerate and allow it to chill until it reaches a spreadable yet thick consistency.
- Once the frosting has reached the desired consistency, spread it generously over the cooled chocolate cake with an angled spatula.
- If desired, you can decorate the frosted cake with additional chocolate shavings, sprinkles, or other decorations of your choice.
NOTES
NUTRITION
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galidink says
can i use this recipe for mini cupcakes ?
Fay says
You sure can!
Sheila Barnard says
Delicious
Fay says
Thanks> I'm so happy you like it!
Bev says
19/12/2025 I made this for my son’s work do and all I can say is OMG it nearly didn’t get there. It’s absolutely delicious and the frosting is to die for. My son said everyone absolutely loved it and said there was not left by the end of the afternoon. It’s definitely a keeper and I will be making it again . Thank you for sharing your recipe.
Fay says
How fabulous! I'm trilled everyone loved it. Thank you for posting your feedback 🙂
Linda Stanley says
I’d love to make the chocolate cake with fudge frosting for my grandchildren. They would love it.
However, the cake ingredients are in America measurements and the frosting is in metric! I don’t understand American measurements so could you possibly give the cake ingredients in grams as well?
Thank you so much.
Linda
Fay says
Hi Linda, I completely understand the confusion with different measurements. I chose to use cups for this recipe because it’s very forgiving and works really well with simple volume measurements. I’ve tested it using both metric and imperial, and it turns out beautifully every time, so you don’t need to worry about it being exact. I love how flexible it is. I hope you enjoy making it, and I’d love to hear how it turns out!
Natasha Sparkes says
Hi could I ask why the cake has been measured in cups but the ganache has grams. I’m in the uk so we use grams or ounces. Thank you
Fay says
Hi Natasha, that’s a great question. The cake batter is designed to be quite flexible, so using cups works really well and still gives a consistent result without needing exact weights. The ganache is a bit more precise, which is why I’ve listed it in grams to help get the right texture and consistency. I’ve made the cake both ways and it comes out just as well, so you can feel confident using the cup measurements.