Preheat your oven to 350 degrees and rub an 8x8 inch pan with coconut oil.
In a large bowl, using an electric hand mixer, beat together the mashed banana, coconut sugar and apple cider vinegar.
Add in all the remaining bar ingredients, except the cocoa nibs, and stir until a thick batter forms. Then, stir in 3 Tbsp of the cacao nibs, reserving the rest for later.
Spread the batter evenly into the prepared pan and sprinkle with the remaining cacao nibs
Bake until lightly golden, and a toothpick inserted in the middle comes out clean, about 20 minutes. Be careful not to over-bake them.
Let them cool COMPLETELY in the pan.
Once cooled, cut into squares. Mix the powdered peanut butter with the water and drizzle over the bars.