Preheat oven to 350F and line a loaf pan with parchment paper (or spray with oil).
Mix wet ingredients together in one bowl. Mix dry ingredients together in a separate bowl.
Add dry ingredients to bowl with wet and stir until just combined.
Fold in chopped dark chocolate, then evenly pour batter into loaf pan.
Transfer to preheated oven and bake for 40 minutes, or until knife or toothpick inserted in the center comes out clean.
Notes
Feel free to use whatever type of nut butter you want -- peanut, cashew, almond, or even sunflower seed butter.I haven't made this with a vegan or flax egg so I'm not sure how well it will turn out!To make oat flour, pulse 2 cups of organic old-fashioned oats in a food processor until a flour-life consistency forms. Alternatively, you can use almond flour.