Blueberry Lemon Tres Leche Cupcakes with Toasted Meringue Frosting
Makes 16-18 cupcakes
6 large eggs, separated
1 cup plus 2 tablespoons sugar, divided
3 tablespoons lemon zest
6 tablespoons butter, melted and cooled
1 tablespoon rum or vanilla extract
1 1/2 cups cake flour
1 1/4 teaspoons baking powder
1/2 teaspoon salt
1 1/2 cups fresh or frozen blueberries
14 ounces sweetened condensed milk
12 ounces evaporated milk
3/4 cup whole milk
For the frosting
4 large egg whites
1 cup sugar
Pinch of salt
Preheat the oven to 350F degrees. Spray two 12-cup muffin tins with nonstick baking spray or fill them with paper liners.
In the bowl of an electric mixer fitted with the paddle attachment, beat the egg yolks with the sugar at medium speed until light and fluffy, 3 minutes. Add the lemon zest and butter; beat for 2 minutes more. Beat in the rum or vanilla.
In a medium bowl, whisk together the cake flour, baking powder, and salt, then add the dry ingredients to the wet ingredient, mixing until just combined.
In a clean bowl, beat the egg whites with the remaining 2 tablespoons of sugar until soft peaks form. Fold the egg whites into the batter until thoroughly incorporated. Carefully stir in the blueberries (try to avoid breaking them up and turning the batter blue!)
Divide the batter among the muffin cups, filling them about halfway full. Bake for 16-18 minutes, until the cupcakes are golden brown and a toothpick inserted into the center emerges clean.
While the cupcakes are baking, whisk together the condensed milk, evaporated milk, and whole milk.
Allow the cupcakes to cool in the tins for a few minutes, then carefully transfer them to a wire rack placed over a baking sheet. With a serrated knife, cut 1/4-1/2 inch off the top of each cupcake, so that the top is fairly flat. Using a tablespoon, pour the milk mixture over the top of the cupcakes, one at a time, allowing the milks to soak in before adding more. Try to get about 2-3 tablespoons per cupcake.
Place the cupcakes on a plate or in a pan, cover, and chill for at least 6 hours or overnight.
Prepare the frosting: Combine the egg whites, sugar, and salt in a heat-proof bowl and place it over a saucepan of simmering water. Whisk the mixture constantly until it is very warm to the touch and the sugar has dissolved. Immediately transfer to the bowl of an electric mixer fitted with the whisk attachment, and beat at medium-high speed until the mixture has cooled and stiff peaks form.
Transfer the meringue to a piping bag fitted with a large tip, and pipe the meringue onto the chilled cupcakes. Optional: Using a kitchen torch, toast the meringue frosting. Serve as soon as possible!