Chocolate Sheet Cake (with Peanut Butter Frosting)

Name: Chocolate Sheet Cake with Peanut Butter Frosting
Prep time: 20 min
Cook time: 35 min
Ingredients: 1½ sticks unsalted butter, softened ((170g)); 2 cups granulated sugar ((400g)); 4 large eggs, room temperature ((if in a hurry, place in a bowl of warm water for 5 minutes).); 2 ¾ cups All Purpose Flour ((322g)); 1 cup unsweetened cocoa powder (not Dutch processed), measure then sift ((82g)); 2 teaspoons Baking Soda ((10g)); ½ teaspoon Baking Powder ((2g)); ½ teaspoon Salt ((2g)); ¼ cup vegetable oil; 1 cup Sour Cream ((242g) (we use "full fat")); 1 cup Milk ((220g) (We use 2 percent or whole milk)); 2 teaspoons vanilla extract ((8g)); 1 cup Hot Coffee ((220g)); ¾ cup mini chocolate chips (optional) ((we used semi-sweet) Mini chips are lightweight and less likely to sink.); 1 cup Creamy Peanut Butter ((255g) (We recommend something along the lines of Jif Creamy) *See notes); 2 sticks unsalted butter, softened ((226g) ); 4 cups powdered sugar ((460g)); ¼ cup milk, plus 2 Tablespoons ((60g) (adjust amount to your liking for desired consistency)); 2 teaspoons vanilla extract ((8g)); pinch of salt; 4 oz Semi-Sweet or Dark Chocolate; 3 oz Heavy Cream; Mini Reese's Cups, sliced

This delicious chocolate sheet cake is moist, rich, and has a fantastic balance of chocolate and peanut butter!

Chocolate Sheet Cake, sliced, on a cake plate.

We've frosted this decadent chocolate sheet cake with peanut butter frosting, topped it with a simple chocolate glaze, and decorated with Reese's cups!

Table of Contents

Why we Love It

There is so much to love about this Peanut Butter Chocolate Sheet Cake! It comes together quickly, makes plenty of batter to fill a 9x13 sheet cake pan, and serves a crowd--perfect for birthday cakes, potlucks, and other celebrations. Plus, we love any excuse to break out the peanut butter frosting- it is divine! ;0)

Ingredients at a Glance

Here's a quick look at our ingredients- you can find the full recipe at the bottom of our post!

Unsalted butter (we add salt separately)
White sugar adds sweetness and moisture
Eggs add richness, structure, and moisture
All Purpose Flour
Unsweetened Cocoa Powder (Use your favorite. We like Hershey & Ghirardelli)
Baking Soda, Baking Powder, & Salt
Vegetable Oil (we use canola oil)
Sour Cream Adds richness. We use "full fat"
Milk (We like 2 percent or whole)
Very Hot Coffee Enhances the flavor of the chocolate. If you cannot use coffee, you can substitute with very hot water-- the hot liquid helps the cocoa to bloom/intensify.
Mini Chocolate Chips (Optional but we love the added chocolate flavor!)

**We paired our cake with delicious Peanut Butter Frosting (creamy peanut butter, butter, butter, milk, vanilla, and confectioners sugar). We also used a rich chocolate glaze of mini chocolate chips & heavy cream!

Frequently Asked Questions

FAQs

We love cake recipes with sour cream. The sour cream adds richness and makes for a really nice texture. Some of our other favorite Sour Cream Cakes are our Lemon Cake from Cake Mix, Toffee Pecan Caramel Cake, Red Velvet Cake, and Sour Cream Pound Cake.

Yes, just as with most of our cakes, this Chocolate Sheet Cake freezes perfectly. If you'd like to work in advance, you cake bake this sheet cake, cool, and then place/turn it out onto a foil-wrapped cake board or tray etc. Then, wrap with plastic wrap followed by foil. Freeze for up to three months.

To thaw, remove from the freezer, unwrap after about 20 minutes, and continue to thaw to desired amount for decorating. (Some decorators like to decorate partially frozen cakes as they are less fragile.)

There are so many frostings that would be great with this recipe. Our Classic Chocolate Buttercream is a great choice, Chocolate Cream Cheese Frosting, Coconut Cream Cheese Frosting, Seven Minute Frosting, Classic Buttercream, Espresso Cream Cheese Frosting as used on Mocha Cupcakes, and so many more.

Many of our chocolate cake recipes include coffee. I've never had anyone say that they could taste the coffee, it just enhances the flavor of the chocolate. You'll want the coffee to be very hot as it helps to bloom the cocoa powder as well, deepening the chocolate flavor. If you do not want to use coffee, you can substitute hot water.

How to Make a Chocolate Sheet Cake

You can find the full, printable recipe at the bottom of this post. Here is a quick look at our steps.

Preheat the oven to 325 degrees F, grease and flour a 9x13 sheet cake pan, lined with parchment.
Dry Ingredients: In a separate bowl, add the flour, sifted cocoa, baking soda, baking powder and salt. Whisk to blend and set aside.

Bowl of dry ingredients for Chocolate Cake.

Sour Cream Mixture: In another bowl, combine the one cup sour cream, vanilla extract, vegetable oil, and milk and set aside. (not the coffee yet).
In the bowl of your mixer, mix the softened butter until smooth, and then gradually add the sugar. Mix on medium speed for 4-5 minutes or until light and fluffy.
Add the eggs one at a time, mixing after each egg just until the yellow of the yolk has blended.
Mixing on low speed, alternately add the flour mixture and sour cream mixture to the sugar mixture, beginning and ending with the dry ingredients. Mix just until combined.
With mixer on low speed, slowly pour in the hot coffee. We used instant espresso dissolved into very hot water but any hot coffee will do. If you don't want to use coffee, you can use hot water instead.
Gently fold in the mini chocolate chips and scoop into the prepared pan. Bake for 35-40 minutes or until a toothpick comes out clean (or with just a few crumbs attached).

Allow the freshly baked cake to cool for 5-10 minutes before turning out. Make sure to cool completely before frosting.

Freshly baked Chocolate Sheet Cake, still in the pan.

Chocolate Glaze for Chocolate Sheet Cake

We also made a simple and delicious chocolate glaze to decorate the cake with. This is an optional step, but it adds another layer of chocolate and looks so pretty!

This simple chocolate ganache can be made in the microwave, with just two ingredients- chocolate and heavy cream.

We combined semi-sweet mini chocolate chips with heavy cream in a small, microwave-safe bowl. Then, we microwaved in small increments until the chocolate was *almost* melted, and stirred until smooth.

The glaze will thicken a bit as it cools. Once cooled (but still soft), you can spread it over the frosted cake.

photo grid of chocolate chips and cream in a bowl, and the finished ganache.

Frosting and Decorating

Once the Chocolate Sheet Cake had cooled, we frosted it with our favorite Peanut Butter Frosting. This frosting is SO delicious, pipes perfectly, and is really easy to make.

I frosted the cake with a smooth finish, and then piped a chunky braided border using a IM star piping tip. The cake is on a clear platter ;0) We'll wipe away the frosting around the base at the end before adding our candy border.

Piping a braided border on top of the cake.

Next, I spread on the chocolate glaze- yum! I love the contrast of the chocolate against the peanut butter frosting. I started with a dollop of ganache in the center of the cake, and then gently spread it close to the borders. I made little ripples here and there with my spatula.