Preheat the oven to 350°F (180°C). Line an 8×8-inch (20×20 cm) baking pan with parchment paper.
Put the cottage cheese in a blender or food processor.
Blend the cottage cheese until smooth.
Add applesauce, honey, eggs, instant coffee powder, salt and vanilla extract.
Blend again until smooth.
Transfer the mixture into a bowl.
Add the oat flour and cocoa powder.
If using chocolate chips or nuts, fold them in.
Pour batter into the prepared pan and spread evenly.
Sprinkle some more chocolate chips on top if desired.
Bake for 20–22 minutes, or until a toothpick inserted comes out mostly clean (a few crumbs are okay, don’t overbake).
Let brownies cool completely in the pan before cutting into squares.