8 ounces high-quality white chocolate (I used Ghirardelli) chopped
1 3/4 cups all purpose flour
1 teaspoon baking powder
1/2 teaspoon coarse kosher salt
1 cup sugar
3/4 cup (1 1/2 sticks) unsalted butter, room temperature
1 tablespoon vanilla extract
1/2 cup canned unsweetened coconut milk
3 large egg whites
Whisk flour, baking powder, and salt in medium bowl. Using electric mixer, beat sugar, butter, and vanilla in large bowl until blended. Add warm white chocolate to sugar mixture; stir to combine. Add flour mixture in 3 additions alternately with coconut milk in 2 additions, beating batter just to combine between additions. Batter will be stiff.
Using clean dry beaters, beat egg whites in medium bowl until soft peaks form. Gently fold egg white mixture into batter in 3 additions. The first addition can be stirred quite vigorously, but when folding in the last two additions, be gentle, as you don't want to break the egg white foam.
Divide batter among muffin cups (about 1/4 cup each). Bake until tester inserted into center comes out clean, about 25 minutes. Cool completely before frosting.
White Chocolate Frosting
6 ounces (3/4 of 8-ounce package) cream cheese, room temperature
6 tablespoons (3/4 stick) unsalted butter, room temperature
1/4 cup powdered sugar
1/2 teaspoon vanilla extract
1/4 teaspoon coarse kosher salt
Stir white chocolate, if using, in ametal bowl set over saucepan of barely simmering water until melted and smooth. Cool slightly. Using electric mixer, beat cream cheese, butter, sugar, vanilla, and salt in medium bowl until fluffy. Gradually beat in melted white chocolate. Let cool until thickened to spreadable consistency.
Spread frosting over cupcakes. Drain Candied Kumquats (see below); arrange kumquats decoratively atop cupcakes. Leftover candied kumquats can be stirred into your favorite pound cake for delicious results!