Prep the pan: Line an 8x8-inch pan with parchment, leaving overhang for easy lifting.
Make the cookie dough: In a bowl, whisk 1 cup almond flour, 1/2 cup protein powder, 1 tablespoon cocoa powder (optional), 1/2 teaspoon baking powder, and a pinch of salt.
Add wet ingredients: Stir in 1/3 cup applesauce, 2 tablespoons nut butter, 2–3 tablespoons maple syrup, and 1 teaspoon vanilla. Fold in mini chips if using.
The dough should be soft but not sticky; add a spoonful of flour if needed.
Form the bottom layer: Press half the dough evenly into the pan. Use damp hands or a spatula to smooth it.
Chill briefly: Freeze the bottom layer for 10 minutes to firm up.
Mix the filling: In a clean bowl, combine 1 1/2 cups Greek yogurt, 1/2 cup protein powder, 2–3 tablespoons sweetener, 1 teaspoon vanilla, and a pinch of salt. Stir until thick and smooth.
Adjust sweetness and thickness to taste.
Add mix-ins: Fold in berries, chips, or a swirl of nut butter if you like.
Assemble: Spread the filling over the chilled bottom layer. Crumble the remaining cookie dough over the top and gently press to form an even upper layer.
Freeze: Cover and freeze for 3–4 hours, or until set and sliceable.
Slice and serve: Lift out using the parchment, cut into 8–12 sandwiches, and enjoy slightly softened for best texture.