In a large mixing bowl, combine the oat flour, protein powder, maple syrup, peanut butter, vanilla extract, and a pinch of salt. Stir the mixture until all the ingredients are well combined.
Line an 8x8 inch baking dish with parchment paper and grease it lightly. Transfer the mixture into the dish and press it down firmly to create an even layer.
In a small saucepan or using a double boiler, melt the dark chocolate chips and coconut oil together over low heat. Stir continuously until the chocolate is smooth and well combined with the coconut oil.
Pour the melted chocolate over the pressed mixture in the baking dish, spreading it evenly with a spatula.
Sprinkle sea salt on top of the chocolate layer for added flavor.
Place the dish in the refrigerator for at least thirty minutes to allow the bars to set.
Once the bars are firm, remove them from the fridge and lift the parchment paper to easily transfer the slab onto a cutting board.
Cut the chilled mixture into bars of your desired size.
Serve and enjoy