Prepare Your Dish: Line an 8x8 inch baking dish with parchment paper, leaving an overhang on the sides.
Combine Dry Ingredients: In a large mixing bowl, combine the rolled oats, protein powder, ground flaxseed, and a pinch of sea salt.
Warm Wet Ingredients (Optional): Gently warm the nut butter and honey (or maple syrup) over low heat until just melted and smooth, then add vanilla extract.
Combine Wet and Dry: Pour the warm wet mixture into the dry ingredients, adding almond milk, and mix vigorously until a thick dough forms.
Fold in Chocolate Chips (Optional): If using, fold in mini chocolate chips until distributed evenly.
Press into Dish: Transfer the mixture into the prepared dish, pressing down firmly and evenly.
Chill: Cover with plastic wrap and refrigerate for at least 2 hours until firm.
Cut and Serve: Once firm, lift out of the dish using the parchment paper, cut into bars, and enjoy.