Strawberry Cupcakes with Strawberry Buttercream Frosting

cake flour

baking powder

baking soda

salt

unsalted butter (, softened)

+ 2 Tbsp granulated sugar

large egg

large egg whites

fresh strawberry puree*

buttermilk**

vanilla extract

drops red food coloring ((optional))

diced strawberries ((dice into about 1/4-inch pieces))

Diced and whole strawberries for topping ((about 1 lb small strawberries))

+ 2 Tbsp strawberry puree

unsalted butter (, nearly at room temperature)

salted butter (, nearly at room temperature)

powdered sugar

vanilla extract

drops red food coloring ((optional))