Blend the cottage cheese. Add cottage cheese to a food processor or blender and blend until mostly smooth. This step ensures a silky batter and tender crumb.

Whisk the wet ingredients. In a large bowl, whisk eggs, granulated sugar, brown sugar, oil, Greek yogurt, vanilla, and the blended cottage cheese until combined and creamy.

Combine the dry ingredients. In a separate bowl, whisk flour, baking powder, baking soda, salt, and lemon zest (if using).

Bring the batter together. Add dry ingredients to the wet and fold gently with a spatula just until a few streaks of flour remain. Do not overmix.

Prep the blueberries. Toss blueberries with 1 tablespoon flour to help prevent sinking. Fold them into the batter gently to avoid bursting.

Fill the cups. Divide batter evenly among muffin wells. Each should be about 3/4 full. Sprinkle tops with coarse sugar if you like a crunchy lid.

Bake. Bake for 18–22 minutes, or until tops are lightly golden and a toothpick comes out with a few moist crumbs. If using frozen berries, add 1–2 minutes.

Cool. Let muffins cool in the pan 5 minutes, then transfer to a rack. This prevents soggy bottoms and keeps the crumb fluffy.

Serve. Enjoy warm or at room temperature. They’re excellent plain or with a swipe of butter or honey.