Preheat oven to 350℉. Line a muffin tin with baking cups and spray lightly with nonstick cooking spray, set aside.
Dissolve instant coffee in hot water, set aside.
In a mixer bowl cream butter and sugar until well blended. Add eggs, bananas, coffee mixture, vanilla, flour, salt, baking soda, and baking powder.
Fold in chocolate chips and walnuts, blending well, scraping bottom and sides of the bowl.
Scoop batter into baking cups, filling almost full. Bake 25 - 30 minutes or until done.
Cool on a wire rack.
