Step 1: Preheat your oven to 350°F (175°C).
Step 2: Prepare the muffin tin with parchment paper liners or grease lightly with butter.
Step 3: Mash the bananas in a mixing bowl until smooth, leaving a few lumps if desired.
Step 4: Add softened butter, brown sugar, granulated sugar, egg, and vanilla to the bananas. Whisk until smooth.
Step 5: In a separate bowl, whisk together flour, baking powder, and baking soda.
Step 6: Gradually fold the dry ingredients into the wet mixture until just combined.
Step 7: Fold in chocolate chips and toffee bits until evenly distributed.
Step 8: Scoop batter into muffin tin, filling each cup about 3/4 full.
Step 9: Bake for 20-25 minutes, or until a toothpick comes out clean.
Step 10: Cool in the tin for 5 minutes before transferring to a wire rack.