Strawberry cheesecake cupcakes

Preheat oven to 350 F and prepare 6 – 8 muffin tins. Sprinkle about 1 t of the crushed graham cracker into the bottom of each prepared muffin tin.
In a small bowl, mix together the flour, baking powder & salt. In a large bowl, cream together butter & sugar until light & fluffy and then add the vanilla & beat on a low-speed. Then add half the flour mixture until incorporated then mix in the sour cream or yogurt. Add remaining flour & mix until just blended.
In another bowl beat the egg whites until stiff, glossy peak appear, about 2 minutes. Gently fold 1/3 of the egg into the batter until combined, do not over mix the egg whites or the cake will fall flat. Add remaining egg and fold in the chopped strawberries. Fill each muffin tin about 3/4 of the way and bake for about 20 minutes depending on your oven. You can test the doneness by sticking a toothpick through the center, if it comes out clean it is ready to take out!