Line an 8×8-inch baking pan with parchment paper, leaving some overhang for easy removal. Pro tip: Use binder clips to secure the parchment to the sides of the pan for perfectly straight edges.
In a medium bowl, combine peanut butter, maple syrup, vanilla extract, and salt (if using), stirring until completely smooth. Add the coconut flour and mix until fully incorporated. The mixture should be firm enough to hold together but still slightly sticky.
Press the peanut butter mixture firmly and evenly into your prepared pan. For the smoothest surface, use the bottom of a measuring cup to press and flatten the mixture, creating a compact, even layer.
In a microwave-safe bowl, combine chocolate chips and coconut oil. Microwave in 30-second intervals, stirring between each, until completely melted and smooth. This typically takes 1-1.5 minutes total.
Pour the melted chocolate over the peanut butter layer, tilting the pan gently to create an even coating. For a professional finish, tap the pan gently on the counter to remove any air bubbles.
For visual appeal, use a toothpick to create gentle swirls in the chocolate, or sprinkle with flaky sea salt, chopped peanuts, or a light dusting of cocoa powder while the chocolate is still wet (optional).
Refrigerate the bars for at least 1 hour until completely set. For best results, let them set for 2 hours or overnight for the cleanest cuts and firmest texture.
Once set, lift the entire dessert out using the parchment overhang. For clean cuts, use a sharp knife dipped in hot water and wiped dry between slices.