Easy Chocolate Sheet Cake

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Easy chocolate sheet cake with fudge brownie like cake and a chocolate buttercream frosting. Served cold, this old-fashioned chocolate cake is easy to make and delicious. 

Where did all the sheet cakes go?

Anyone else wondering why you don’t see as many sheet cakes anymore? I’m not talking about the large supermarket chain birthday cakes, I’m talking about these old-fashioned delicious sheet cakes like this chocolate sheet cake. Don’t get me wrong, I love a decorated circle stacked cake like this painted buttercream cake, chocolate spider web cake or striped buttercream cake. However, I think there is something special about a classic sheet cake that can be served up in the pan and doesn’t take hours or days to decorate.

How to Make this Chocolate Sheet Cake

I don’t know how many years my mother-in-law has been making this cake, but it has been a family favorite for a long time. This is the cake my husband requests every year and it never disappoints. It’s so simple to make. I love that both the batter and frosting start out the same way. For the batter, you melt the butter, cocoa, water and oil and then pour it over the dry ingredients. For the frosting, you melt the butter, cocoa and milk and pour over the powdered sugar.

Tips Before You Get Started

• When melting your butter, cocoa powder, water and oil make sure to remove it from the heat as soon as it reaches the boiling point. Otherwise, it may burn.
• Before baking, cover the edges with foil (like shown above) to prevent the edges from burning.
• Pour the frosting over the hot cake. Trust me. Just pour.
• Make sure the frosting is somewhat runny. If it is too stiff, it will not pour over the cake. If you find the frosting is too thick, add a little more milk.
• If you don’t have buttermilk, add 2 tsp of vinegar to milk and let it sit for 5 minutes.

Chocolate Sheet Cake – Served Cold

The original recipe does not say to chill this cake, but my husband’s family has been serving it cold as long as I can remember. I think putting it in the fridge to chill allows all the flavors to soak up into this cake. Unlike a traditional chocolate cake like I used in my spiderweb cake, this cake is similar to a fudge brownie. It is rich, moist and full of chocolate flavor. The chocolate frosting is the most delicious chocolate icing. Everyone in my house is always fighting over the bowl.

Print Pin

5 from 1 vote

Chocolate Sheet Cake

Ingredients

Cake

• 2 cups flour (300g)
• 2 cups sugar (415g)
• 1 tsp baking soda
• 1/2 cup butter (115g)
• 1/4 cup cocoa powder (20g)
• 1/2 cup buttermilk *
• 2 large eggs
• 1 tsp vanilla
• 1 cup water
• 1/2 cup oil (vegetable or canola)

Frosting

• 1/2 cup butter (115g)
• 1/4 cup cocoa powder (20g)
• 9 tbsp milk
• 2 lbs powdered sugar (907g)
• 1 tsp vanilla

Instructions

Cake

• Preheat oven to 400 degrees (200c)
• If you don't have buttermilk, add 2 tsp of vinegar to milk and let it sit for 5 minutes
• Combine dry ingredients (flour, sugar and baking soda) in a large mixing bowl
• In a saucepan, heat to boiling point the butter, cocoa powder, water and oil
• Pour over dry ingredients and mix on low speed until combined
• Add vanilla to buttermilk and add the mixture slowly to the batter
• Add eggs, one at a time
• Increase mixer speed to medium and mix thoroughly until combined
• Pour batter into a greased 11x15" pan. Cover edges with aluminum foil to prevent burning the sides.
• Bake for 20 minutes

Frosting

• Put powdered sugar into a large mixing bowl
• In a saucepan, melt butter, milk, and cocoa powder
• Pour over powdered sugar
• Once cake is cooked, pour frosting over hot cake
• Chill for at least 2-3 hours or overnight

Notes

*If you don't have buttermilk add 2 tsp of vinegar to milk and let it sit for 5 minutes.