Preheat oven to 350 degrees Fahrenheit (175 degrees Celsius).

Spray a 10- by 14-inch (26- by 36-centimeter) baking pan or a nine-inch (20-centimeter) round springform pan with cooking spray.

For the crust, place all the ingredients in a medium bowl and stir; or mix in the bowl of an electric mixer until the dough just comes together.

Press dough evenly into prepared pan, making sure that the dough is spread all the way to all the walls within the pan, and a bit up the sides.

Refrigerate for 10 minutes (if you don’t have time, you can skip this step). Bake crust for 15 minutes and allow to cool in the baking pan.

In a large bowl, place all ingredients except blueberries and whisk until well blended.

Place the pan on a metal baking sheet.

Pour the blueberries over the baked crust. Pour in the lemon mixture and move the blueberries around so that they are evenly distributed.

Bake for 20–25 minutes. Lower the oven temperature to 325 degrees Fahrenheit (160 degrees Celsius) and bake for another 20 minutes or until the topping is set. Do not overbake; the topping can wiggle gently when it’s in the oven. Cut into squares after fully cooled and refrigerated.