Step 1: Preheat the Oven - Begin by preheating your oven to 350°F (175°C). This ensures that your muffins bake evenly.
Step 2: Prepare the Muffin Tin - Line your muffin tin with parchment paper or muffin liners for easy removal.
Step 3: Mix the Dry Ingredients - In a large mixing bowl, whisk together flour, baking soda, baking powder, and salt.
Step 4: Combine the Wet Ingredients - In another bowl, mash the bananas and mix in sugar, egg, melted butter, and cinnamon.
Step 5: Combine the Mixtures - Gradually add the dry ingredients to the wet ingredients, stirring gently until just combined.
Step 6: Prepare the Crumb Topping - In a small bowl, mix brown sugar, flour, ground cinnamon, and butter until crumbly.
Step 7: Fill the Muffin Tin - Spoon batter into the muffin tin, filling each cup about two-thirds full and sprinkle with crumb topping.
Step 8: Bake and Enjoy - Bake for 18-20 minutes, or until a toothpick comes out clean. Allow to cool before transferring to a wire rack.
