Preheat the oven to 350°F (175°C). Line a 12-cup muffin tin with paper liners or lightly grease with cooking spray.
Make the batter:
In a large bowl, combine the flour, baking powder, soda, and salt. Mix well with a whisk to distribute the ingredients.
In a large bowl with a hand mixer or your stand mixer, beat the butter and sugar until it’s light and airy, for about 5 minutes, using a spatula to scrape down the sides of the bowl when necessary.
Add the eggs, one at a time, and beat until combined. Add the vanilla extract and the blended cottage cheese and stir just until it’s mixed in, being careful not to overmix.
Combine the wet and dry ingredients in the bowl. Use a fork or a rubber spatula to stir the mixture just until the dry ingredients are combined. The batter will be thick. Fold the blueberries into the batter.
Use a big tablespoon or large scoop to fill the muffin tins nearly to the top.
Bake:
Bake the muffins for 20 to 22 minutes, until the tops are golden brown and a toothpick inserted in the middle comes out clean.
Remove the muffin pan from the oven and let the muffins cool completely before taking them out.
Serve & store:
Enjoy these muffins lightly warmed or at room temperature.
Store leftovers in an airtight container at room temperature (on the counter) for 1 day, in the refrigerator for up to 5 days, or in the freezer for up to 3 months.
Notes
If using frozen berries, add them directly to the batter. There's no need to thaw them first.