2vanilla beanshalved lengthwise, seeds scraped and reserved
2cupsall-purpose flour
2teaspoonsbaking powder
¼teaspooncoarse salt
Instructions
Preheat oven to 350 degrees F/180 degrees C. Line a 12-cup muffin pan with paper baking cups; set aside.
Put butter and granulated sugar into the bowl of an electric mixer fitted with the paddle attachment; mix on medium speed until pale and fluffy, about 3 minutes. Add egg whites, milk, vanilla extract, and vanilla seeds; mix until combined, scraping down sides of bowl as needed. Add flour, baking powder, and salt; mix until just combined.
Divide batter among paper baking cups in muffin pan, filling each cup about ¾ full. Bake in preheated oven until very light golden brown, approximately 24-27 minutes. Transfer pan to a wire rack; let cool completely. Frost with Vanilla Bean Buttercream Frosting. Cupcakes can be stored, covered loosely with plastic wrap, in the refrigerator.