• Step 1: Preheat your oven to 375°F (190°C). Grease a 9×13-inch baking dish with butter or non-stick cooking spray.
• Step 2: In a large mixing bowl, whisk together the all-purpose flour, granulated sugar, baking powder, baking soda, and salt.
• Step 3: In a separate bowl, combine the buttermilk, eggs, and melted butter. Whisk until well combined.
• Step 4: Pour the buttermilk mixture into the dry ingredients and stir just until combined, being careful not to overmix. Gently fold in the blueberries.
• Step 5: Pour the batter into the prepared baking dish, spreading it evenly.
• Step 6: Bake for 35-40 minutes, or until the casserole is golden brown and a toothpick inserted in the center comes out clean.
• Step 7: Allow the casserole to cool for 5-10 minutes before serving. Enjoy warm, with your favorite toppings like maple syrup, whipped cream, or powdered sugar.