1 cup Classic White Chips
6 ounces White Chocolate Baking Bar
1 3/4 cups plus 2 tablespoons all-purpose flour
3/4 teaspoons baking powder
1/4 teaspoon salt
3/4 cup (1-1/2 sticks) unsalted butter, at room temperature
1 1/2 cups granulated white sugar
3 large eggs
3/4 cup whole milk
3/4 teaspoon fresh lemon juice
1/2 teaspoon pure vanilla extract
4 large egg whites
1 cup plus 2 tablespoons granulated white sugar
1 cup plus 2 tablespoons (2-1/4 sticks) unsalted butter, at room temperature
- Preheat the oven to 350°F.
- Line 14 cupcake molds or muffin tins with paper liners or spray with nonstick spray.
- Sift together the flour, baking powder, and salt.
- To make the cupcakes, in large bowl, beat the 3/4 cup butter and 1-1/2 cups sugar with an electric mixer on medium speed until light. Add the 3 eggs, one at a time, scraping down the sides of the bowl between each addition. Stir together the milk, lemon juice, and the vanilla. On low speed, add half the milk mixture.
- Mix until incorporated; scrape down the sides of the bowl. Add the remaining milk mixture and the dry ingredients in the same manner.
- Divide the batter amount the 14 cupcake molds.
- Bake on the middle oven rack for about 15 minutes, or until a tester inserted in the center of the cupcakes comes out clean.
- Cool cupcakes in their pans for 10 minutes. Then unmold and cool on a wire rack.
- To make the frosting, melt the white chocolate baking bar in the top of a double boiler, or in a heatproof bowl over barely simmering water, stirring occasionally until smooth.
- Cool to room temperature. While the chocolate is cooling, combine the egg whites and 1 cup plus 2 tablespoons sugar in the bowl of an electric mixer.
- Place the bowl in a pot of simmering water so the water comes a third of the way up the bowl.
- Lightly whisk the egg whites just until hot to the touch, about 1-1/2 minutes.
- Remove the bowl from the pot on whisk on high speed until very thick and cooled to room temperature, about 5 minutes.
- Decrease the mixer to medium-low speed and add the butter, 1 tablespoon at a time, mixing the butter in before adding the next tablespoon.
- Add the melted white chocolate and vanilla and mix until smooth. Frost the top of each cupcake and sprinkle them with the white chips.