In a medium saucepan, gently heat the peanut butter and honey (or maple syrup) over low heat, stirring until both are melted and well combined. Remove from heat and let cool slightly.
In a large mixing bowl, combine the rolled oats, coconut flour, salt, and crushed nuts. If using chocolate chips, reserve them for later.
Pour the warm peanut butter mixture into the dry ingredients and add the vanilla extract. Mix well until everything is fully combined and forms a thick dough-like consistency.
If desired, fold in the reserved chocolate chips.
Line an 8x8 inch square pan with parchment paper. Press the mixture evenly into the bottom of the pan, smoothing the top with a spatula.
Refrigerate for at least 2 hours or until firm. Once set, remove from the pan and cut into bars.
Store the bars in an airtight container in the refrigerator for up to two weeks, or freeze for longer storage.
Notes
Stack the bars neatly on a plate and sprinkle some crushed nuts on top for a decorative touch. You can also wrap them individually in parchment paper for a great on-the-go snack!