Butterscotch–Peanut Butter Cupcakes

If you love peanut butter cookies, just wait until you try these cupcakes! Smooth peanut butter is best for the buttercream. Don’t be tempted to use old-fashioned or natural peanut butter, because it may separate.

MAKES: 18 cupcakes

PREP TIME: 40 minutes

COOKING TIME: about 20 minutes

INGREDIENTS:

CUPCAKES

• 1 ½ cups all-purpose flour
• ½ cup cake-and-pastry flour
• 1 ½ tsp baking powder
• ½ tsp baking soda
• ½ tsp fine sea salt
• 1 cup butterscotch chips
• ½ cup unsalted butter, softened
• 1 cup firmly packed dark brown sugar
• 3 large eggs
• 1 Tbsp vanilla extract
• 1 cup buttermilk

PEANUT BUTTER BUTTERCREAM

• ½ cup unsalted butter, softened
• 1 cup smooth peanut butter
• 1 tsp vanilla extract
• ½ tsp fine sea salt
• 3 to 4 cups icing sugar, sifted
• 2 Tbsp whipping cream (35%)
• ½ cup roasted salted peanuts, chopped

INSTRUCTIONS:

1. Preheat the oven to 350°F. Line two muffin pans with 18 large paper liners, then set aside. Pour water into any empty wells to prevent burning.
2. Whisk together both flours, the baking powder, baking soda, and salt in a medium bowl. Stir in the butterscotch chips. Set aside.
3. In a large bowl and using an electric mixer, beat the butter with the sugar until light and fluffy.
4. Beat in the eggs one at a time, beating well after each addition and scraping down the sides of the bowl once or twice. Beat in the vanilla extract.
5. Add the flour mixture to the sugar mixture alternately with the buttermilk, making three additions of flour and two of buttermilk, and beginning and ending with the flour. Stir until well combined.
6. Fill the paper liners about two-thirds full with batter. Bake until the cupcakes spring back when lightly touched and a wooden skewer inserted in the center of a cupcake comes out clean, about 20 minutes.
7. Let the cupcakes cool in the pans for 10 minutes, then remove to a wire rack and let cool completely. (The undecorated cupcakes can be refrigerated in an airtight container for up to 4 days.)
8.  For the peanut butter buttercream, in a large bowl and using an electric mixer, beat the butter until pale and fluffy. Beat in the peanut butter, vanilla extract, and salt.
9. Add about 1 ½ cups of the icing sugar and beat on low speed. Beat in the cream and enough of the remaining icing sugar to make a smooth, fluffy, spreadable buttercream.
10. Using an offset spatula or a piping bag, swirl the buttercream on top of the cupcakes. Sprinkle with the peanuts. (The decorated cupcakes can be refrigerated in an airtight container for up to 3 days. Bring them to room temperature before serving.)