Preheat the Oven: Preheat to 375°F (190°C) and line a muffin pan with paper muffin cups.
Mix Dry Ingredients: In a large bowl, whisk together flour, sugars, baking powder, baking soda, and salt.
Mix Wet Ingredients: In a small bowl, whisk eggs, melted butter, yogurt, vanilla extract, and lemon zest until smooth.
Combine Mixtures: Pour wet ingredients into dry and mix gently. Don’t overmix – a few lumps are okay.
Fold in Blueberries: Gently fold in blueberries using a spatula. If using frozen, toss them in a little flour first to prevent streaking.
Fill Muffin Tin: Spoon batter evenly into prepared muffin cups, filling 3/4 full. Sprinkle tops with coarse sugar if desired.
Bake: Bake for 18–20 minutes or until tops are golden and a toothpick comes out clean.
Cool: Let muffins cool in the tin for 5 minutes, then transfer to a wire rack.