Step 1: Preheat your oven to 375°F (190°C) and line an 8x8 inch baking pan with parchment paper, leaving an overhang on the sides for easy removal.
Step 2: In a large bowl, combine whole wheat pastry flour, rolled oats, brown sugar, baking powder, and salt for the crust. Mix well.
Step 3: Add the melted butter and vanilla extract to the dry ingredients. Mix with a fork or your fingertips until crumbly and moist.
Step 4: Press about two-thirds of the crumb mixture evenly into the bottom of the prepared baking pan. Set aside the remaining crumb mixture for the topping.
Step 5: In another bowl, gently toss the blueberries with cornstarch, granulated sugar, lemon juice, and lemon zest. This is a key part of making great healthy blueberry recipes.
Step 6: Pour the blueberry mixture evenly over the crust in the baking pan.
Step 7: Crumble the reserved oat mixture over the blueberry filling.
Step 8: Bake for 35-40 minutes, or until the topping is golden brown and the blueberry filling is bubbling.
Step 9: Let the bars cool completely in the pan on a wire rack before lifting them out using the parchment paper overhang. This is crucial for clean cuts, ensuring your healthy blueberry recipes look as good as they taste.
Step 10: Once cooled, cut into 12 squares and serve. Enjoy these delightful healthy blueberry recipes!