Preheat the oven to 350°F. Spread the chopped macadamia nuts on a baking sheet and toast for 6 to 8 minutes, until lightly golden and fragrant, then let them cool.
Blend the cottage cheese until completely smooth. In a large bowl, whisk the blended cottage cheese, melted butter, brown sugar, egg yolk and vanilla until glossy.
Add the all-purpose flour, almond flour, protein powder, baking soda and salt, and stir until combined. Fold in the toasted macadamia nuts and white chocolate chips, then cover and chill for 30 minutes.
Line 2 baking sheets with parchment paper. Scoop the dough into 2 tablespoon balls, place them 2 inches apart and press a few extra white chocolate chips on top if you like.
Bake for 10 to 12 minutes, until the edges are golden and the centers look slightly underbaked. The almond flour and cottage cheese keep the centers rich and chewy.
Cool on the baking sheets for 10 minutes, then move to a wire rack.