Preheat oven to 350 degrees.
In a food processor, combine walnuts, drained raisins, and banana. Blend for about 15 seconds, or until mixture is smooth.
In a seperate bowl, combine remaining ingredients. Mix well then add banana mixture. Stir until fully combined.
Line an 8x8 pan with parchment paper. Add batter and spread on bottom of the pan evenly. Top with banana slices, if desired.
Bake for about 1 hour, or until bars are toasted.
Let cool and slice.
Enjoy!!