Preheat the oven to 350 F and line an 8 x 8 pan with parchment paper.

In a medium sized pot on low heat add the nut butter and maple syrup to soften and melt. 

Once the nut butter has become a little runny and thin, add the sweet potato puree and stir to combine. Remove from the heat and let cool for 10 minutes.

Stir in all the remaining ingredients (except chocolate) and using a wooden spoon combine until ingredients are roughly evenly distributed. It will be a very dry and sticky texture.

Pour the mixture into a prepared pan and press down evenly to cover the whole pan with about 3/4" thick mixture. Use a masher if you can't get the surface to be even. 

Bake for 15 minutes then remove from oven and cool before slicing. 

If desired, drizzle melted chocolate on top for an extra treat!