Preheat the oven to 425°F (220°C) and line a 12-cup muffin pan with paper liners.
Blend the cottage cheese, eggs, oil, sugar, vanilla, and lemon juice until smooth.
Whisk the flour, baking powder, baking soda, and salt together in a large bowl. Add the wet mixture and fold just until combined, about 10-15 folds. Leave the batter thick and slightly lumpy.
Toss the blueberries with 1 tablespoon flour, then gently fold them and the lemon zest into the batter.
Divide the batter between the 12 muffin cups, filling them almost to the brim and mounding the centers slightly. Sprinkle with coarse sugar if using.
Bake at 425°F (220°C) for 5 minutes. Without opening the oven, reduce the temperature to 375°F (190°C) and bake for another 17-21 minutes, until golden and a toothpick comes out clean.
Cool in the pan for 5 minutes, then transfer to a wire rack.