Preheat the oven to 375°F. Grease a 9x13-inch baking pan or line it with parchment paper.
In a large bowl, whisk together the flour, sugar, and baking powder.
Cut in the cold butter until the mixture resembles coarse crumbs.
Add the egg and mix until the dough comes together.
Press about 3 cups of the mixture firmly into the bottom of the prepared pan. Reserve the remaining crumbs for the topping.
In a medium bowl, combine the chopped strawberries, sugar, and cornstarch. Stir until the berries are evenly coated.
Spread the strawberry mixture evenly over the pressed crust.
Sprinkle the remaining crumb mixture evenly over the strawberry layer.
Bake for 50 minutes, or until the top is lightly golden. If the topping browns too quickly, tent with foil.
Cool completely before slicing into 16 bars.