Preheat oven to 375°F (190°C). Grease a 9×13-inch baking dish.
In a large bowl, combine 1 3/4 cups flour, 3/4 cup granulated sugar, baking powder, and salt.
Add chilled butter cubes and use a pastry blender or your fingertips to mix until the mixture resembles coarse sand.
Stir in the egg and milk until a soft dough forms.
Pat half of the dough evenly into the prepared baking dish.
In a separate bowl, combine the cherries with cornstarch and 3 tbsp granulated sugar.
Sprinkle the cherry mixture evenly over the crust.
Use the remaining dough as the top layer; pat it over the cherries, creating a crumbly texture for the topping.
Bake for 35 minutes, or until the topping is golden brown and the filling is bubbling.
Let cool completely before cutting into 16 bars.
Serve and store in an airtight container at room temperature for up to 2 days.