Ingredients

The following ingredients have 8 Servings
  • ½ cup unsalted butter (, at room temperature (113 grams))
  • ½ cup granulated sugar ((115 grams))
  • 1 large egg
  • ¼ cup whole milk ((2 fl oz))
  • 1 teaspoon vanilla extract
  • 1 cup all-purpose flour ((124 grams))
  • 1 ½ teaspoons baking powder ((4 grams))
  • ½ teaspoon salt ((2 grams))
  • 1 tablespoon grapefruit zest
  • ½ cup powdered sugar (, sifted (50 grams))
  • 1 tablespoon grapefruit zest
  • 2 tablespoons fresh grapefruit juice

Instruction

  • Preheat oven to 400°F. Line a muffin pan with paper liners or grease with non-stick cooking spray.
  • In the bowl of a stand mixer fitted with a paddle attachment, beat the butter and sugar until light and creamy, about 3-4 minutes. Add the egg and mix until incorporated. Add the milk and vanilla extract and mix until combined.
  • In another bowl, combine the flour, baking powder, salt, and grapefruit zest. Add the dry ingredients to the wet ingredients and mix until just combined. Batter will be thick.
  • Spoon into the prepared muffin pan, filling each cup about ⅔ full. Bake until golden and a toothpick inserted into the center of a cupcake comes out clean, about 12-14 minutes. Let cool in the pan for 5 minutes, then turn out onto a wire rack to cool completely.
  • To make the icing, combine the powdered sugar, grapefruit zest, and grapefruit juice until smooth and there are no lumps. Add more juice if necessary to achieve desired consistency. Spoon onto the cooled cupcakes and let sit for a few minutes to firm up before serving.
  • Store cupcakes in an airtight container at room temperature for up to 3 days.