Preheat oven to 350º F. Spray a 9x13 baking dish with nonstick baking spray, brush with homemade pan release, or spread with a thin coating of butter and then lightly flour the pan, removing any excess flour.
In a large mixing bowl, whisk together 2 cups of flour, baking powder, salt, and sugars until well-combined.
Combine milk and lemon juice and zest in a separate bowl. Set aside for later use.
Pour melted butter into dry ingredients and stir together until really well-combined with a rubber spatula. Add eggs one at a time, combining well after each addition.
Add milk and lemon mixture to the batter and stir well.
Gently fold in blueberries. Pour batter into prepared baking dish.
Sprinkle blueberries from the topping ingredients onto the top of the cake batter. Then, sprinkle entire top of cake with 3 tablespoons of granulated sugar to form a sugary crust on the baked cake.
Bake cake for 40-45 minutes until a cake tester or toothpick inserted in the center comes out clean. You can follow my tips for how to tell when your cake is done. Allow to cool completely, about 15-20 minutes before serving.
Store cake slices in an airtight container for up to 3 days.