Banana Nut Muffins

Preheat oven, prepare muffin pan: Preheat the oven to 350°F. Line a muffin pan with paper liners. Combine wet ingredients and sugar: Thoroughly mash the bananas in a large bowl. Stir the melted butter into the bananas. Mix in the sugar, egg, coffee and vanilla extract. Combine dry ingredients: Whisk together the flour, baking soda, and salt. Add dry ingredients into wet, add nuts: Add the flour mixture to the banana mixture, a third at a time, stirring until it is just incorporated. (Do not over-mix! Over-mixing will result in dense, tough muffins.) Fold in the chopped walnuts or pecans. Fill muffin cups, and bake: Lightly spoon the mixture into a prepared muffin tin. Bake at 350°F for 20-25 minutes. Check for doneness by pressing down on the top of the muffin. If it bounces back, it's done. You can also test by inserting a skewer or other tester into the center of a muffin. If it comes out clean, it's done. Cool on a rack.