Preheat the oven to 350°F (177°C). Line a 12-cup muffin pan with cupcake liners. Whisk the cake flour, baking powder, baking soda, and salt together.

Beat the butter and sugar until creamed, about 3 minutes. Add egg whites, beat for 2 minutes. Add sour cream and vanilla, beat for 1 minute.

Slowly pour in the milk with the dry ingredients on low speed until just combined. Fold in the crushed Oreos.

Spoon batter into liners, filling 2/3 full. Bake for 19–22 minutes, or until a toothpick comes out clean.

Cool cupcakes in the pan for 20 minutes, then remove to a rack to cool completely before frosting.