Chocolate Buttercream Sheet Cake

Name: Chocolate Buttercream Sheet Cake
Prep time: 20 min
Cook time: 30 min
Total time: 50 min
Yield: 12 servings
Ingredients: 1 ¾ cups all-purpose flour; 1 ½ cups sugar; ¾ cup unsweetened cocoa powder; 1 ½ tsp baking powder; 1 ½ tsp baking soda; 1 tsp salt; 2 large eggs; 1 cup whole milk; ½ cup vegetable oil; 2 tsp vanilla extract; 1 cup boiling water; 1 cup unsalted butter, softened; 3 ½ cups powdered sugar; ½ cup unsweetened cocoa powder; 1 tsp vanilla extract; 2-4 tbsp heavy cream

Highlighted under: Modern Baking Inspiration

I absolutely love baking this Chocolate Buttercream Sheet Cake when I want to impress my family and friends. It’s rich, decadent, and incredibly easy to make, which has made it a go-to recipe in my kitchen. The velvety chocolate buttercream frosting adds an indulgent touch, while the sheet cake format makes it perfect for gatherings. Whether it's a birthday party or a casual weekend treat, this cake never fails to satisfy sweet cravings. Trust me, once you serve this cake, everyone will be coming back for seconds!

Created by

Linnea Porter

Last updated on 2026-02-16T04:01:35.532Z

When I first attempted this Chocolate Buttercream Sheet Cake, I knew I had to nail the frosting. I experimented with different butter-to-sugar ratios and discovered that a 2:1 ratio yielded the perfect creamy consistency without being overly sweet. It took a couple of tries, but the result was simply phenomenal.

Another tip I learned along the way is to always sift the cocoa powder before mixing it into the batter. This ensures a smoother texture, preventing any lumps from ruining the cake's overall appearance and taste. The combination of these small adjustments has made this recipe a cherished favorite among my loved ones.

Why You Will Love This Recipe
Indulgent chocolate flavor with a creamy buttercream layer
Easy to make yet impressive for gatherings
Perfect balance of sweetness without being overwhelming

Tips for Achieving the Perfect Cake Texture

For a moist and tender Chocolate Buttercream Sheet Cake, measuring the flour accurately is crucial. Lightly spoon the flour into a measuring cup and level it off with a knife. Too much flour can lead to a denser cake, while too little may cause it to collapse. Using cake flour instead of all-purpose flour can also yield a lighter texture; just replace it with the same amount in the recipe.

When mixing your batter, be careful not to overmix once the wet and dry ingredients are combined. Overmixing can develop gluten, resulting in a tougher cake texture. Mix just until you no longer see dry flour, and then gently incorporate the boiling water, which helps create that desired moist crumb. This is one of my favorite tricks for achieving cake perfection!

Buttercream Frosting Secrets

To obtain a rich and creamy buttercream, the butter must be at room temperature but not melted. This will help you achieve that light and airy texture. If your butter was refrigerated, giving it about 30 minutes on the countertop typically does the trick. If you’re short on time, you can microwave it for 10-second intervals, but watch it carefully to prevent melting.

When it comes to achieving that smooth, glossy frosting, the addition of heavy cream is key. Start with 2 tablespoons and gradually add more until you reach the desired spreading consistency. If you accidentally add too much cream, you can thicken it back up by mixing in a bit more powdered sugar or cocoa powder, ensuring your frosting stays beautifully spreadable!

Ingredients

Gather the following ingredients to create this delicious Chocolate Buttercream Sheet Cake:

Cake Ingredients

1 ¾ cups all-purpose flour
1 ½ cups sugar
¾ cup unsweetened cocoa powder
1 ½ tsp baking powder
1 ½ tsp baking soda
1 tsp salt
2 large eggs
1 cup whole milk
½ cup vegetable oil
2 tsp vanilla extract
1 cup boiling water

Buttercream Frosting Ingredients

1 cup unsalted butter, softened
3 ½ cups powdered sugar
½ cup unsweetened cocoa powder
1 tsp vanilla extract
2-4 tbsp heavy cream

Make sure to have these ingredients ready to bring your cake to life!

Instructions

Follow these steps to prepare your delicious Chocolate Buttercream Sheet Cake:

Preheat the Oven

Preheat your oven to 350°F (175°C) and grease a 9x13 inch baking pan. It’s essential to preheat for a precise bake.

Mix Dry Ingredients

In a large bowl, mix together flour, sugar, cocoa powder, baking powder, baking soda, and salt until well combined.

Combine Wet Ingredients

In another bowl, whisk together eggs, milk, oil, and vanilla extract until smooth. Then, gradually mix this into the dry ingredients.

Add Boiling Water

Carefully stir in boiling water to the batter, which will loosen it up. The batter will be thin, but that’s perfect for a moist cake!

Bake the Cake

Pour the batter into the prepared pan and bake for 30-35 minutes or until a toothpick inserted in the center comes out clean.

Cool the Cake

Allow the cake to cool in the pan for 10 minutes, then remove it and transfer to a wire rack to cool completely.

Prepare the Buttercream

In a bowl, beat the softened butter until creamy, then gradually add powdered sugar and cocoa powder. Add vanilla and enough heavy cream to achieve spreading consistency.

Frost the Cake

Once the cake is completely cool, spread the buttercream evenly over the top of the cake. Feel free to get creative with your frosting design!

Now you’re ready to serve and enjoy your delightful Chocolate Buttercream Sheet Cake!

Pro Tips

For an extra touch, try adding chocolate shavings or sprinkles on top of the frosted cake for a festive look.

Storage and Make-Ahead Tips

This Chocolate Buttercream Sheet Cake can be made a day in advance, which makes it an excellent choice for busy hosts. Once cooled completely, wrap the cake tightly in plastic wrap and store it at room temperature or in the fridge. Just remember to frost it the day you plan to serve it to keep that buttercream fresh and decadent.

If you have leftover cake, you can store it in an airtight container at room temperature for up to three days. If you want to keep it longer, consider freezing the unfrosted cake. Simply wrap it in plastic wrap and aluminum foil, then it can be frozen for up to three months. Thaw it in the fridge overnight before frosting and serving.

Serving and Presentation Ideas

For a visually appealing presentation, consider garnishing your Chocolate Buttercream Sheet Cake with chocolate shavings or a dusting of cocoa powder. Adding fresh berries or whipped cream on the side can also provide a lovely contrast and a pop of color that elevates the dessert experience for your guests.

This cake pairs wonderfully with a scoop of vanilla ice cream. For a fun twist, you can make dessert sandwiches by layering buttercream between two pieces of cake, serving them warm for a delightful treat that kids and adults alike will enjoy. Just remember to adjust the frosting quantities accordingly!

Questions About Recipes

→ Can I use a different type of flour?

Yes, you can substitute all-purpose flour with gluten-free flour, but the texture might vary.

→ How long can I store the cake?

The cake can be stored in an airtight container at room temperature for up to 3 days, or in the refrigerator for up to a week.

→ Can I make this cake ahead of time?

Absolutely! You can bake and frost the cake a day in advance; just keep it refrigerated until serving.

→ What can I use instead of eggs?

You can use unsweetened applesauce or a flax egg as egg substitutes for a vegan version.