Ingredients
Equipment
Method
Preheat and prep
- Preheat the oven to 375°F and grease a 9x13 baking dish, making sure the corners are coated to prevent sticking (no visible dry spots).
- Whisk all-purpose flour, sugar, baking powder, baking soda, and salt together in a bowl until the mixture looks uniform in color.
Mix batter
- Whisk buttermilk, large eggs, melted butter, and vanilla extract together until smooth, with no streaks of egg visible.
- Stir the wet mixture into the dry ingredients until just combined, stopping as soon as no dry flour remains to keep the bake tender.
Bake and finish
- Pour the batter into the prepared dish and scatter fresh or frozen blueberries evenly across the top so they’re dotted throughout.
- Bake at 375°F for 35–40 minutes until the center is set and the top is golden and lightly springy when gently pressed.
- Dust with powdered sugar, slice into squares, and serve with warm maple syrup for drizzling.
Notes
Pro tip: use an oven-safe 9x13 dish and distribute blueberries evenly before baking so every square gets berries. Store leftovers covered in the refrigerator for up to 3 days; rewarm individual squares in the oven or microwave until hot. Freezing is yes—freeze cooled squares airtight for up to 2 months and thaw overnight in the fridge. For a lighter option, swap half the all-purpose flour for whole-wheat pastry flour for a slightly nuttier flavor while keeping the casserole tender.
