Tender, bakery-style blueberry muffins enriched with cottage cheese for extra moisture and protein, finished with a crisp, fragrant lemon-sugar crust.
Preheat the oven to 425°F. Line a 12-cup muffin pan with baking cups.
Make the lemon sugar: In a small bowl, rub together 2 tablespoons granulated sugar and 1 teaspoon packed lemon zest. Set aside.
Blend wet ingredients: In a blender, combine cottage cheese, 3/4 cup granulated sugar, melted unsalted butter, eggs, lemon juice, and vanilla. Blend until smooth.
Mix dry ingredients: In a large bowl, whisk together all-purpose flour, baking powder, baking soda, and fine sea salt.
Combine: Pour the blended wet mixture over the dry ingredients and stir just until combined.
Portion batter: Spoon about 2 tablespoons of plain batter into each muffin cup. Gently fold the blueberries into the remaining batter with a single stir, then divide this blueberry batter among the cups, filling until heaping.
Top and bake: Sprinkle the lemon sugar over the muffins. Bake 5 minutes at 425°F, then (without opening the oven) reduce heat to 350°F and bake about 15 minutes more, until golden and a toothpick comes out clean.
Cool: Let muffins cool in the pan for 10 minutes, then transfer to a wire rack to cool completely.