Preheat the oven to 350°F (175°C) and line an 8×8-inch baking pan with parchment paper.
Blend cottage cheese in a food processor or blender until smooth. This helps create a silky texture in the brownies.
Mix wet ingredients – In a bowl, whisk together melted butter, cottage cheese, cocoa powder, granulated sugar, brown sugar, eggs, and vanilla extract until smooth.
Combine dry ingredients – In a separate bowl, whisk flour, baking powder, and salt.
Fold together – Gradually mix the dry ingredients into the wet mixture until just combined. Stir in chocolate chips if using.
Bake – Pour the batter into the prepared baking pan and spread evenly. Bake for 30 minutes or until a toothpick inserted in the center comes out with a few moist crumbs.
Cool and serve – Let the brownies cool in the pan for at least 10 minutes before slicing and serving.