Preheat oven to 425 F. Cover baking sheet with parchment paper and spray with nonstick cooking spray. Set aside.
In large bowl, mix flour, baking powder, sugar and salt. Add milk, egg and melted butter; mix until smooth.
Pour batter onto prepared baking sheet and smooth into even layer that covers pan. Top with strawberries, blueberries and chocolate chips.
Bake 5-7 minutes, or until cooked and golden brown. Let cool slightly before cutting into squares.