Cupcakes:
1 ½ cups cake flour
1 teaspoon baking powder
1/8 teaspoon salt
6 tablespoons whole milk
1 teaspoon vanilla extract
¼ teaspoon almond extract
6 tablespoons butter, room temperature
1 cup sugar
6 large egg whites
¼ teaspoon cream of tartar
Preheat the oven to 350ยบ. Line 12 muffin tins with papers.
Sift flour, baking powder, and salt into a bowl and set aside. In a measuring cup, stir the milk and vanilla and almond extracts together.
Using a mixer, beat the butter and sugar until blended and light, about 2 minutes. Add the flour mixture in 3 additions and the milk mixture in 2 additions, beginning and ending with the flour mixture. Set aside
In another bowl with clean beaters, beat the egg whites and cream of tartar on low until the whites are foamy and the cream of tartar dissolves, about 1 minute. Beat on medium-high until soft peaks form. Use a spatula to fold one-third of the whipped egg whites into the batter, and then fold in the remaining whites until no streaks of egg white remain.
Fill each paper with 1/3 cup of batter, to about ¼ inch below the top. Bake about 23-25 minutes. The tops should remain pale or barely brown just on the edges. Cool cupcakes, and then fill.
Lime Filling:
¼ cup butter
1/3 cup fresh lime juice
2 large eggs
2 large egg yolks
1 cup sugar
2 tablespoons cornstarch, dissolved in ¼ cup water
1 teaspoon grated lime zest
In a saucepan, heat the butter and lime juice until the butter melts and the mixture is hot. In a bowl, whisk the eggs, egg yolks and sugar together to blend them, then whisk in the dissolved cornstarch. Whisking constantly, slowly pour the hot butter and lime juice into the yolk mixture. Return the mixture to the saucepan and cook over medium heat, stirring constantly just until it comes to a boil and thickens; it will take about 6 minutes. Immediately remove from the heat and stir in the lemon zest. Press plastic wrap directly onto the surface of the sauce and refrigerate until cold.
Fill the Cupcakes:
Cut a cone-shaped piece, about 1 inch across and 1 inch deep, out of the middle of the top of each cupcake and set aside. Spoon 1 tablespoon of lime filling into each hole. Replace the cone pieces of cupcake. Immediately frost the cupcakes.
Frosting:
½ cup butter, room temperature
3 cups confectioners’ sugar
1 teaspoon vanilla
3 to 4 tablespoons milk
½ cup sweetened coconut
lime wedges
Using a mixer on low, beat the butter, powdered sugar and vanilla together with 3 tablespoons milk, then add up to 1 tablespoon more milk if needed to form a creamy, smooth, spreadable frosting. Use a pastry bag and star tip to frost the top of each cupcake. Sprinkle the frosting very lightly with coconut. Top with a small wedge of lime.
