Preheat and prep: Heat the oven to 425°F (220°C).
Line a 12-cup muffin tin with liners. This high initial heat helps create tall muffin tops.
Mix the dry ingredients: In a large bowl, whisk flour, baking powder, baking soda, and salt. Set aside.
Whisk the wet ingredients: In a separate bowl, whisk sugar, eggs, melted butter, oil, yogurt, milk, and vanilla until smooth.
If using lemon zest, whisk it in now.
Combine gently: Pour the wet mixture into the dry. Stir with a spatula just until a few streaks of flour remain. Do not overmix—lumpy batter is fine.
Prepare the blueberries: Toss the blueberries with 1 tablespoon of flour to lightly coat.
This helps prevent them from sinking. Fold them into the batter with a few gentle strokes.
Rest the batter (optional but helpful): Let the batter sit for 10–15 minutes. This brief rest hydrates the flour and boosts the rise.
Fill the tin: Divide the batter evenly among the 12 cups, filling them to the top for bakery-style domes.
Sprinkle each muffin with coarse sugar.
Bake hot, then lower: Bake at 425°F (220°C) for 5 minutes. Without opening the oven, reduce the temperature to 350°F (175°C) and bake 14–17 minutes more, until the tops are golden and a toothpick comes out with a few moist crumbs.
Cool: Let muffins cool in the pan for 5 minutes, then transfer to a rack to cool completely. This prevents soggy bottoms.
Serve: Enjoy warm or at room temperature.
They’re great plain, with butter, or a swipe of lemon curd.