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

In a large mixing bowl, whisk together the oat flour, protein powder, and sea salt until no lumps remain.

Add the natural peanut butter and maple syrup to the dry mixture. Stir with a stiff spatula until a thick, crumbly dough forms.

Gradually add the almond milk, one tablespoon at a time, mixing thoroughly until the dough is moist enough to hold together when pressed between fingers but not sticky.

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

In a small microwave-safe bowl, combine the dark chocolate chips and coconut oil. Heat in 30-second increments, stirring in between, until completely smooth.

Pour the melted chocolate over the pressed bar mixture and spread evenly to the edges.

Place the pan in the refrigerator for at least 30 minutes to allow the base to firm up and the chocolate to set.

Using the parchment overhang, lift the block out of the pan and place it on a cutting board.

Slice into 12 equal rectangular bars using a sharp knife. Store in an airtight container in the refrigerator for up to 10 days.