Ingredients:

  • 1 cup (125g) all-purpose flour, spooned and leveled
  • 1/2 cup (42g) Hershey's Special Dark cocoa powder (or other unsweetened cocoa)
  • 1 teaspoon baking soda
  • 1/2 teaspoon baking powder
  • 1/2 teaspoon salt
  • 1/3 cup (80ml) vegetable oil
  • 1 cup (200g) granulated sugar
  • 1 large egg, at room temperature
  • 1 teaspoon pure vanilla extract
  • 1/2 cup (120ml) buttermilk, at room temperature
  • 1/2 cup (120ml) hot coffee (decaf or regular, black) or hot water
  • 5 Tablespoons (71g) unsalted butter, softened to room temperature
  • 1 cup (250g) creamy peanut butter (avoid natural varieties for this frosting)
  • 1 cup (120g) confectioners' sugar (powdered sugar)
  • 1/3 cup (80ml) heavy cream
  • 1 teaspoon pure vanilla extract
  • 1/4 teaspoon salt
  • Optional: Crushed Reese's Pieces, for topping

Instructions:

  1. Preheat oven to 350°F (177°C). Line muffin tin(s) with cupcake liners.
  2. Whisk together flour, cocoa powder, baking soda, baking powder, and salt in a medium bowl.
  3. In a large bowl, whisk together oil, sugar, egg, vanilla, and buttermilk until combined.
  4. Pour dry ingredients into wet ingredients. Add hot coffee/water. Whisk until just combined. Batter will be thin - don't worry!
  5. Pour batter into cupcake liners, filling about 2/3 full.
  6. Bake for 20-22 minutes, or until a toothpick inserted in the center comes out clean (or with a few moist crumbs).
  7. Let cupcakes cool in the pan for 10 minutes, then transfer to a cooling rack to cool completely. Important: Frosting warm cupcakes is a recipe for disaster!
  8. Beat softened butter until creamy. Add peanut butter, confectioners' sugar, heavy cream, vanilla, and salt. Beat on low until combined, then increase speed and beat for 3 minutes until light and fluffy. Adjust consistency with more confectioners' sugar (if too thin) or cream (if too thick).
  9. Frost cooled cupcakes using a piping bag or knife. Top with crushed Reese's Pieces, if desired.