Ingredients
Scale
For the cupcakes
- 1 1/2 cups (165 g) sifted cake flour
- 1 teaspoon (4.6 g) baking powder
- 1/4 teaspoon (1.5 g) baking soda
- 1/4 teaspoon (1.4 g) salt
- 1 stick (113 g) unsalted butter, softened to room temperature
- 1 cup (220 g) granulated sugar
- 3 large egg whites (120 g), at room temperature
- 1 teaspoon (3 g) pure vanilla extract
- 1/2 cup (120 g) sour cream, at room temperature
- 1/2 cup (120 g) champagne, at room temperature
For the frosting
- 2 sticks (226 g) unsalted butter, softened to room temperature
- 1 pound (450 g) powdered sugar
- Pinch of salt
- 1 teaspoon (3 g) pure vanilla extract
- 2–4 tablespoons (15-30 g) champagne
Instructions
For the cupcakes
- Preheat oven to 350°F/177°C. Line a muffin pan with cupcake liners. Set aside.
- In a medium bowl, sift together flour, baking powder, baking soda and salt. Set aside.
- In a large bowl using a hand-held mixer or stand mixer fitted with the paddle attachment, beat together softened butter and sugar on medium-high speed until smooth and creamy, 4-5 minutes. Scrape down the sides of the bowl as needed. Beat in egg whites, one at a time, until combined. Scrape down the sides of the bowl and beat in vanilla until mixed well and then sour cream. With the mixer on low speed and in three parts, alternately add the dry ingredients and the champagne to the batter, beginning and ending with the dry ingredients. Beat until just combined.
- Fill cupcake liners 3/4 full and bake for 16-18 minutes, or until a toothpick inserted in the center comes out clean.
- Allow cupcakes to cool completely in the pan set on a wire rack before frosting.
For the frosting
- In a large bowl using a hand-held mixer or stand mixer fitted with the paddle attachment, beat the butter on medium-high speed for 5 minutes. With the mixer on low speed, slowly add in the powdered sugar and salt, beating until the sugar is completely incorporated. Add the vanilla and beat until incorporated. Add, one tablespoon at a time, the champagne until desired consistency is achieved. Beat the buttercream on medium-high for an additional 5 minutes.
Notes
- Make Ahead: Make cupcakes up to 1 day in advance. Cover in an airtight container at room temperature. Champagne buttercream can be made up to 1 week in advanced and stored covered in an airtight container in the refrigerator. When ready to use bring to room temperature and rewhip for 5 minutes using a handheld mixer or stand mixer fitted with the paddle attachment.
- Freezing: Freeze cupcakes frosted or unfrosted for up to 2-3 months. Thaw overnight in the refrigerator and allow to sit for 30 minutes at room temperature before serving.
- Baker’s tools: KitchenAid Stand Mixer, spatula, cupcake pan, cupcake liners, pastry bags, pastry tip.
- Prep Time: 25 minutes
- Cook Time: 20 minutes
- Category: Cakes & Cupcakes