Preheat and prep: Heat the oven to 400°F (200°C). Line a 12-cup muffin pan with paper liners. Set aside 1 tablespoon of the flour to toss with the blueberries.
Mix dry ingredients: In a large bowl, whisk 2 cups all-purpose flour, 3/4 cup sugar, 2 teaspoons baking powder, 1/4 teaspoon baking soda, and 1/2 teaspoon kosher salt until combined.
Whisk wet ingredients: In a separate bowl, whisk 2 large eggs, 1/2 cup plain yogurt or sour cream, 1/3 cup milk, 1/4 cup melted unsalted butter (slightly cooled), 1/4 cup neutral oil, and 1 1/2 teaspoons vanilla.
Add 1 teaspoon lemon zest if using.
Combine gently: Pour the wet mixture into the dry. Stir with a spatula until just combined. The batter should be thick and slightly lumpy—don’t overmix.
Fold in berries: Toss 1 1/2 to 2 cups blueberries with the reserved tablespoon of flour.
Gently fold them into the batter, saving a few to dot on top.
Fill the pan: Divide the batter evenly among the muffin cups, filling each about 3/4 full. Top with the reserved blueberries and sprinkle with coarse sugar if you like.
Bake high, then lower: Bake at 400°F (200°C) for 6 minutes to help the muffins rise. Without opening the oven, reduce the temperature to 350°F (175°C) and bake 12–15 more minutes, until golden and a toothpick comes out with a few moist crumbs.
Cool briefly: Let the muffins cool in the pan for 5 minutes, then transfer to a rack.
They’re best slightly warm, but they hold well at room temperature.