Preheat the oven to 375°F and line a baking sheet with parchment paper.
Blend the cottage cheese until completely smooth. In a large bowl, whisk together the flour, baking powder, sugar and salt.
Add the blended cottage cheese to the flour mixture and stir until a shaggy dough forms. Turn it out onto a floured surface and knead for 1 to 2 minutes until smooth and only slightly tacky, adding a little more flour if needed.
Toss the blueberries in 1 teaspoon of flour, then gently knead them into the dough, trying not to crush them.
Divide the dough into 6 equal pieces. Roll each piece into a 7-inch rope and pinch the ends together to form a ring. Place the bagels on the baking sheet.
Brush the bagels with beaten egg and sprinkle with coarse sugar.
Bake for 22 to 25 minutes, until puffed and deep golden. Let them cool for at least 10 minutes before slicing so the inside finishes setting.