- Preheat the oven to 350°F and line 24 muffin cups with baking cups.
- In a medium bowl, whisk together flour, baking powder and salt.
- In a large bowl, cream together the sugar and the butter until light and fluffy. Beat in vanilla extract, then beat in the egg whites one at a time, making sure each is fully incorporated before adding the next.
- Working in 4 or 5 additions, alternately add the flour mixture and the milk to the sugar mixture. Keep the mixer on low speed while you do this. When just combined, stir in the crushed Oreos.
- Spoon batter evenly into muffin tins, filling each about 2/3 full.
- Bake for 15-18 minutes at 350°F, until a toothpick comes out clean (a few chocolate cookie crumbs are fine, but not batter).
- Cool completely on a wire rack before frosting.
- Store in an airtight container if not serving the same day.
- Note: If you only have a 12-cup muffin tin, the batter will not suffer from sitting around for a few minutes while the first batch bakes. Just be sure to let the pan cool completely before filling it up again.
- Variation: To make plain vanilla cupcakes, simply omit the Oreos. You might end up with only about 18 cupcakes, but as long as you fill the tins about 2/3 full, the baking time will be the same.
- Quick Vanilla Buttercream Frosting:.
- Combine all ingredients in a large bowl and beat, with an electric mixer, until frosting is creamy, 3-5 minutes.
- Frost cupcakes with frosting using a butter knife or offset spatula. Add as much or as little frosting as desired. If making Oreo cupcakes, garnish with additional chunks of Oreo.