Line an 8x8 inch square baking pan with parchment paper, leaving an overhang on two sides for easy removal.

In a large microwave-safe bowl, combine the cashew butter, sugar-free maple syrup, and melted coconut oil.

Heat the mixture in the microwave for 45-60 seconds, then whisk until the texture is completely smooth and emulsified.

Stir in the vanilla extract and sea salt.

Gradually add the protein powder, stirring with a stiff spatula until a thick, dough-like consistency forms. If the mixture is too dry, add 1 tablespoon of unsweetened almond milk.

Gently fold in two-thirds of the crushed chocolate sandwich cookies.

Transfer the mixture to the prepared baking pan and press down firmly using a flat-bottomed glass or a spatula to create an even layer.

Scatter the remaining crushed cookies over the top and press them lightly into the surface of the fudge.

Place the pan in the freezer for at least 2 hours, or until the fudge is completely firm.

Using the parchment overhang, lift the fudge out of the pan and slice into 16 even squares using a warm, sharp knife.

Store leftovers in an airtight container in the refrigerator for up to 1 week or the freezer for up to 1 month.