Over the summer I made marble cupcakes with swirled chocolate/vanilla frosting, and a chocolate/peanut butter version also seemed like a really good idea. While swirled frosting looks fancy, I promise, it’s not. All you need are two different kinds of buttercream, a sheet of plastic wrap, and a piping bag. For real, that’s all.

This recipe uses a classic chocolate cupcake I’ve made a million times, along with my standard chocolate buttercream and a peanut butter buttercream I found at Sally’s Baking Addiction and tweaked slightly. These cupcakes are for my brother, Andy, who is visiting from North Carolina for the holidays.

Ingredients

For the cupcakes

• 1 1/2 cups flour
• 3 tablespoons cocoa powder
• 1 cup sugar
• 1 teaspoon baking soda
• 1/2 teaspoon salt
• 1 tablespoon vinegar
• 1 teaspoon vanilla
• 3 tablespoons vegetable oil
• 1 cup water

For the frostings and decoration

Chocolate Buttercream

• 8 tablespoons butter, at room temperature
• 1 3/4 cups powdered sugar
• 1/4 cocoa powder
• 1/2 tablespoon vanilla extract
• 2-3 tablespoons heavy cream

Peanut Butter Buttercream

• 5 tablespoons butter, at room temperature
• 1 cup creamy peanut butter
• 1 1/2 to 1 3/4 cups powdered sugar
• 1/3 cup heavy cream
• 1/2 tablespoon vanilla extract
• pinch of salt

Miniature Reese’s Peanut Butter Cups, for garnish

Preparation

Preheat oven to 350 degrees. Line cupcake pans with paper liners; this recipe makes 13-15 cupcakes, depending on how much batter you place in each well.

In a large mixing bowl, combine flour, cocoa powder, sugar, baking soda, and salt. Mix until well-blended, then make three wells for the wet ingredients.

Place vinegar, vanilla, and vegetable oil into the wells; add water and orange zest and mix until the batter is smooth. The mixture will bubble up slightly when you add the water, so just keep mixing until you get a smooth consistency in the batter, which will be fairly thin.

Using a 1/4 cup measure, fill cupcake wells about half full. Bake for 15-17 minutes, until a cake tester comes out clean. Cool in pan for a few minutes, then remove from pan and cool completely on wire racks. Cool completely before frosting.

Make the frostings: for chocolate buttercream, place butter in a mixing bowl and beat for a few minutes using the paddle attachment. Add powdered sugar and cocoa powder and beat on low speed until the sugar and cocoa are fully incorporated into the butter. Add vanilla extract and beat; add heavy cream 1 tablespoon at a time; you may not need all 3 tablespoons.

For the peanut butter buttercream, place butter and peanut butter in a mixing bowl and beat for a few minutes using the paddle attachment. Add 1 cup powdered sugar and beat until the sugar is fully incorporated; add heavy cream, vanilla, and salt and beat to combine. Add remaining 1/2 to 3/4 cup powdered sugar – start with less, as you may not need it all. You want a smooth, pipeable consistency that isn’t too dry, which peanut butter frosting can be.

To frost: Place a sheet of plastic wrap on your counter top and spoon the frostings side by side down the length of the sheet. Wrap it up, snip off one end, and place it in a piping bag fitted with a large star tip like the Wilton 1M. Pipe a swirl onto a plate first, until both kinds are visible. Pipe swirls onto cupcakes and top with mini Reese’s Peanut Butter Cups.