Preheat oven to 325°F and prepare a cupcake pan with paper liners.
Place flour, sugar, baking powder, salt and butter in mixer and beat on low speed until combined.
Pour in milk and vanilla and turn up speed to medium.
Add egg and continue mixing until the batter is smooth.
Make a thin layer of strawberries at the bottom of each cupcake liner.
Fill each cup with batter and bake for 18-20 minutes for mini cupcakes.
Remove from over when toothpick comes out clean, let them sit in pan for a few minutes before transferring to cooling rack.