Prep the pan. Line an 8x8-inch square pan with parchment, leaving overhang on two sides for easy lifting.
Lightly mist with nonstick spray.
Make the cookie dough. In a bowl, whisk almond flour, cocoa, sweetener, baking powder, and salt. Stir in egg, melted coconut oil or butter, and vanilla. Add almond milk 1 teaspoon at a time until a soft, pliable dough forms.
Press and par-bake the bottom layer. Press half the dough evenly into the lined pan.
Use another piece of parchment to press flat and smooth. Bake at 350°F (175°C) for 8–9 minutes until set at the edges. Cool 5 minutes.
Shape the top layer. Roll the remaining dough between two sheets of parchment into an 8x8-inch square (or press into the pan, then lift it out).
Chill this sheet in the fridge to firm up while you make the filling.
Mix the filling. In a medium bowl, whisk Greek yogurt, protein powder, sweetener, vanilla, and salt until silky. If too thick, add 1–2 tablespoons almond milk. Taste and adjust sweetness.
Assemble. Spread the filling evenly over the cooled base.
Carefully place the chilled top cookie layer over the filling. Press gently to adhere. If using, sprinkle mini sugar-free chips on top and press lightly.
Freeze to set. Cover the pan and freeze for 2–3 hours, or until the center is firm enough to cut cleanly.
Portion the bites. Lift the slab out using the parchment.
With a sharp knife, cut into 25–36 small squares (5x5 or 6x6 grid), depending on your preferred bite size.
Soften before serving. Let bites rest at room temperature for 2–5 minutes for the perfect texture. Enjoy cold and creamy.