Chocolate Sheet Cake

Name: Chocolate Sheet Cake
Prep time: 10 min
Cook time: 16 min
Ingredients: 1 box dark chocolate fudge cake mix ((I prefer Duncan Hines)); 3 large eggs; ⅓ cup salted butter, melted; 1 cup boiling water; 1 cup semi-sweet mini chocolate chips ((divided use)); ½ cup salted butter, melted; ⅔ cup cocoa powder; 2 ½ cups powdered sugar; 4-6 Tablespoons heavy cream

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Making a Chocolate Sheet Cake with plenty of servings doesn’t have to be hard when you use this easy recipe with made from scratch frosting!

A SEMI HOMEMADE CAKE RECIPE

This Chocolate Sheet Cake is full of all the delicious chocolate flavors, from the moist dark chocolate cake base to the creamy, made from scratch chocolate frosting on top. It’s fancy enough for a special occasion yet doesn’t require you to be in the kitchen for hours all while being simple enough to whip up that any baking beginner can do it. I love how we can turn an ordinary box of cake mix into a decadent dessert without a bunch of fuss.

A serving utensil holding a slice of Chocolate Sheet Cake.

FREQUENTLY ASKED QUESTIONS

Why do I have to use boiling water?

Boiling water helps to dissolve and activate the cake mix flavors. You’ll get a richer and deeper chocolate flavor by using boiling water. It also helps the ingredients mix easier, creates a chemical reaction with the leavening ingredients in the cake mix so it rises quicker and has a lighter texture.

Can I use a different cake mix?

Sure! I used Dark Chocolate Fudge Cake mix, but you can use any chocolate cake mix, classic chocolate, double chocolate, German chocolate, or Devil’s food cake mix would all work nicely.

What other toppings can I add?

This cake is delicious with the homemade frosting. But you can change things up by adding sprinkles, chopped nuts, or drizzling other syrups or toppings. You could add a drizzle of melted peanut butter, caramel sauce, cut up berries, more chocolate chips, or even chocolate shavings. Any of these options would dress this Chocolate Sheet Cake up even more.

Could this cake be made from scratch?

Absolutely. I would refer you to my Texas Sheet Cake recipe for a totally homemade chocolate sheet cake.

How to store leftovers?

Depending on what’s left of your cake could help you decide how to store it. If you have the whole, uncut cake to keep fresh, just wrap it with plastic or foil. If it’s already been cut, wrap the whole cut piece of cake in foil or plastic wrap to help prevent it from drying out. Additionally, you could store it in an airtight container. You can leave this cake at room temp, or store in the fridge. If chilled, set the cake out for 30 minutes to come to room temperature before serving again.

Can I freeze Chocolate Sheet Cake?

Yes, Chocolate Sheet Cake can be frozen. Carefully wrap your cake tightly in foil or plastic and place it in a freezer safe container or bag and freeze for up to 3 months. Let cake thaw in the fridge overnight or on the counter for a couple of hours before serving again.

A piece of Chocolate Sheet Cake on a plate.

INGREDIENTS NEEDED: (SEE RECIPE CARD BELOW FOR THE FULL RECIPE)

dark chocolate fudge cake mix– I prefer Duncan Hines Dark Chocolate Fudge cake mix, but any brand will do.
large eggs – if possible, allow the eggs to come to room temperature. This helps them to incorporate into the batter much easier.
salted butter- You can use vegetable or canola oil if you don’t want as rich of a flavor. Unsalted butter can be used, just add 1/4 teaspoon of salt.
boiling water– stick to boiling water, not just hot water. Boiling water helps everything mix easier and not turn lumpy.
semi-sweet mini chocolate chips– You can use regular size chocolate chips if needed, or swap out for other baking chips. These can be omitted if needed.
cocoa powder – you want to look for unsweetened cocoa powder.
heavy cream– This is what gives the chocolate frosting that creamy, luscious texture. If you don’t have heavy cream, you can use half and half, milk, or even chocolate milk instead. These alternatives are thinner than heavy cream, so you may need to use less so start with less than the recommended amount then you can always add a little more as you go until it reaches your desired thickness.

Powdered sugar, chocolate cake mix, cocoa powder, mini chocolate chips, heavy cream, melted butter, water, and eggs.

HOW TO MAKE A CHOCOLATE SHEET CAKE

Preheat the oven to 350F degrees. Line a half-sheet baking sheet (10×15-inch) with parchment paper or spray with nonstick cooking spray. Using an electric hand mixer or stand mixer, add the cake mix, eggs, melted butter, and boiling water into a large mixing bowl and mix until smooth and combined. Use a spatula to scrape down the sides and bottom of the bowl, as needed. Gently stir in ¾ cups of mini chocolate chips.

collage of two photos: A mixing bowl with cake mix, eggs, melted butter, and boiling water; chocolate chips being added to cake batter.

Then pour the batter into the prepared baking sheet. Spread out into an even layer. Gently tap the baking sheet on the counter to release any air bubbles. Evenly sprinkle on the remaining ¼ cup of mini chocolate chips.

Place in the oven and bake for 12-16 minutes or until a toothpick comes out clean and the top of the cake bounces back when gently tapped. Remove the cake from the oven and allow it to cool completely before making the frosting (about 1 hour).

collage of two photos: cake batter in baking pan; mini chocolate chips sprinkled on top of cake batter.

When ready to frost the cake: In a medium mixing bowl, using an electric mixer, mix together the melted butter and cocoa powder until smooth. Slowly beat in 1 ½ cups of the powdered sugar until incorporated. Be sure to scrape down the sides and bottom of the bowl with a spatula to incorporate all of the ingredients.

collage of two photos: homemade chocolate frosting prepared in a bowl; powdered sugar added to frosting mixture.

Beat in 2 Tablespoons of heavy cream and then repeat with the remaining powdered sugar and heavy cream (alternating the two) until the frosting reaches the consistency of a light, fluffy frosting. If necessary, add additional heavy cream (a little at a time.) Spread the frosting into a smooth layer onto the cooled cake.