Preheat the oven to 350˚ F. Line cupcake pans with paper liners. In a medium bowl, combine the all-purpose flour, cake flour, baking powder and salt; whisk to blend.
In the bowl of an electric mixer, combine the butter, sugar and vanilla. Beat on medium-high speed until light and fluffy, about 3 minutes. Beat in the eggs and egg white one at a time, mixing well after each addition and scraping down the sides of the bowl as needed. With the mixer on low speed, add the flour mixture in two additions alternating with the milk, mixing each addition just until incorporated. Gently fold in the chopped strawberries with a spatula.
Divide the batter between the paper liners, filling each about ¾-full. Bake until light golden and a toothpick inserted in the center comes out clean, about 25-28 minutes, rotating the pans halfway through baking. Allow to cool in the pans a few minutes, then transfer to a wire rack to cool completely