1-Preheat and Prepare: Start by preheating your oven to 350°F (177°C) and lining pans for about 20 cupcakes. This step ensures even baking and easy removal. Puree 1/2 cup of the chopped strawberries, adding a splash of milk if needed, and set aside the remaining 3/4 cup chopped strawberries for later.

2-Mix the Dry Ingredients: Whisk together the cake flour (or your substitute), baking powder, and salt in a bowl. This creates a solid base for your strawberry cupcakes. Cream the softened butter and sugar until light and fluffy, which takes about 3 minutes and is crucial for the texture.

3-Add Wet Ingredients: Beat in the egg, egg whites, and vanilla extract next. Then, mix in the sour cream, noting that the batter might look curdled, which is normal. Alternately add the dry ingredients and milk, ending with the strawberry puree, and mix just until combined to avoid over-mixing.

4-Bake and Cool: Gently fold in the reserved chopped strawberries into the batter. Fill the cupcake liners about 3/4 full and bake for 21-24 minutes until the tops spring back and a toothpick shows moist crumbs. Let them cool in the pan for 5-10 minutes, then transfer to a wire rack.

5-Make the Frosting: For the strawberry buttercream frosting, grind the freeze-dried strawberries into powder. Beat the butter until creamy, about 2 minutes, then add the confectioners’ sugar, strawberry powder, cream, and vanilla. Beat on low then high speed and adjust salt to taste. Once the cupcakes are cool, frost them and garnish with fresh strawberries if desired.