Here is the recipe:
Tres Leches Cupcake
Recipe Courtesy of Martha Stewart
makes about 20 cupcakes (I halved the recipe and it made 9)
6 large eggs, separated, room temperature
1/4 teaspoon baking soda
1/4 teaspoon coarse salt
1 cup sugar
1/2 cup (1 stick) unsalted butter, melted and cooled
1 cup all-purpose flour, sifted
1 can (12 oz) evaporated milk
1 can (14 oz) sweetened condensed milk
3/4 cup heavy cream
Ground cinnamon, for dusting
1. Preheat oven to 325 degrees. Line standard muffin tins with paper-lines foil liners. With an electric mixer on medium speed, whisk together egg whites, baking soda, and salt until soft peaks form. Reduce speed to low. Add yolks and sugar, whisk until completely combined. Fold in melted butter with a flexible spatula. Add flour in four batches, folding until just combined after each.
2. Divide batter evenly among lined cups, filling each halfway. Bake, rotating tins halfway through, until light golden brown, about 25 minutes. Remove from oven. Immediately poke holes in the tops of cupcakes with a skewer.
3. Whisk together evaporated milk, condensed milk, and heavy cream. With cupcakes still in tins, brush milk mixture over cupcakes, repeating until all liquid has been used. Allow cupcakes to absorb mixture, at least 30 minutes (or up to 1 day in the refrigerator, wrapped tightly in plastic once completely cookl bring to room temperature before serving).
4. To finish, dollop whipped cream generously onto cupcakes, and dust with ground cinnamon. Serve immediately.