1. Combine crushed pretzels and melted butter in a bowl and stir until the entire mixture is moistened. Line a muffin tin* with cupcake paper liners*. Scoop pretzels into the bottom of each liner and flatten with the back of a spoon.

2. Preheat the oven to 180°C (350°F). Combine flour, baking soda, salt, cinnamon, and nutmeg and set aside.

3. In a bowl, whisk egg and add brown sugar, mix until smooth. Stir in vanilla extract and melted butter and mix. Add dry ingredients and mix, then add mashed bananas and mix until the batter comes together. Scoop batter on top of each pretzel crust. Bake for about 15-18 minutes, or until golden brown on top. Let cool completely on a cooling rack.

4. In the bowl of a food processor beat butter and peanut butter until creamy. Add in vanilla extract, then gradually add in sugar and cocoa powder on low speed until entirely combined and smooth. If frosting it a bit too thick, add milk or heavy cream one teaspoon at a time until it becomes a bit creamier. Frost cupcakes, then top with crushed pretzels if desired.