1-1/2cupsblueberriesfresh or frozen, no need to thaw if using frozen
Preheat oven to 350 degrees. Spray a 9x13 inch pan with cooking spray and set aside.
In a large mixing bowl, whisk together flour, sugar, baking powder, and salt. In another bowl, beat together the eggs, milk and oil. Stir into the dry ingredients until incorporated. Fold in the blueberries.
Spread the batter evenly into the 9x13 inch pan and bake for 18-22 minutes. Or until a toothpick inserted in the middle comes out clean. Allow to cool on a wire rack.
To make the Lemon Sauce:
In a medium sized saucepan combine sugar, cornstarch, and lemon peel. Slowly add the water and bring to a boil. Cook and stir for 2 minutes or until it starts to thicken. Remove from the heat and add the butter and lemon juice. Cut the cake into squares and drizzle with lemon sauce.