Created by Luvcookn on October 12, 2023
Step 1: Preheat oven to 375 degrees F.
Step 2: Butter a 9x13-inch baking dish (also line with parchment and butter parchment if you'd like to lift them out easier), set aside.
Step 3: In a large mixing bowl whisk together flour, 1/2 cup granulated sugar, brown sugar, baking powder and salt.
Step 4: In a small mixing bowl, whisk together egg and vanilla until combine.
Step 5: Add egg mixture and cold butter cubes to flour mixture and using a fork or a pastry cutter, cut mixture together until it resembles coarse crumbs.
Step 6: Press 1/2 of the mixture evenly into prepared baking dish.
Step 7: In a separate mixing bowl, whisk together remaining 1/2 cup granulated sugar and cornstarch, stir in lemon juice.
Step 8: Add blueberries then toss mixture to evenly coat, pour and spread coated blueberries evenly over crust in baking dish.
Step 9: Sprinkle remaining crumb mixture over berry layer.
Step 10: Bake in preheated oven about 38 - 42 minutes until top is golden brown.
Step 11: Allow to cool for about 20 - 30 minutes before cutting into squares.
Step 12: Store cooled bars in an airtight container in refrigerator (rewarm in microwave for 10 - 15 seconds if desired).