Ingredients

  • 1 cup all-purpose flour
  • 1 cup white sugar
  • 1/2 cup unsweetened cocoa powder
  • 1 teaspoon baking powder
  • 1/2 teaspoon baking soda
  • 1/2 teaspoon salt
  • 1/2 cup milk
  • 1/4 cup vegetable oil
  • 1 egg
  • 1/2 teaspoon vanilla extract
  • 1/2 cup boiling water
  • 14 miniature peanut butter cup candies
  • 4 egg whites
  • 1 cup white sugar
  • 1 tablespoon peanut butter

Method

  • Preheat oven to 325 degrees F (165 degrees C). Line 14 muffin cups with paper muffin liners.
  • Whisk flour, 1 cup sugar, cocoa powder, baking powder, baking soda, and salt together in a large bowl. Add milk, vegetable oil, 1 egg, and vanilla extract; mix using an electric mixer on low speed until just combined. Increase speed to medium and mix well.
  • Reduce mixer speed to low and slowly pour boiling water into flour mixture. Increase speed to medium and beat for 1 minute.
  • Fill each muffin cup halfway and place a peanut butter cup in the center of each.
  • Bake in preheated oven until golden and tops spring back when lightly pressed, about 20 minutes. Remove from oven and cool in pan for 5 to 10 minutes. Cool completely on a cooling rack before frosting.
  • Set oven rack about 6 inches from the heat source and preheat the oven's broiler.
  • Whisk egg whites and sugar together in a bowl until just combined. Pour egg mixture into a small saucepan and heat over medium heat until sugar is dissolved. Return egg mixture to bowl. Whisk egg mixture on high speed until still peaks form.
  • Place peanut butter in a microwave-safe bowl. Heat on high at 15-second intervals, stirring in between, until peanut butter is thin and creamy. Gently fold melted peanut butter into egg whites. Transfer peanut butter frosting to a piping bag.
  • Pipe frosting onto cooled cupcakes.
  • Toast cupcakes under preheated broiler until lightly browned, about 1 minute.