Preheat your oven to 375°F (190°C) and line a muffin tin with liners or grease it lightly.

Mash the bananas in a large mixing bowl until smooth. A few small lumps are okay—they add texture!

Add the wet ingredients: Stir in the melted butter, brown sugar, egg, and vanilla extract. Mix until well combined.

Incorporate the sourdough discard: Gently fold it into the wet mixture. Don’t overmix—this keeps the muffins tender.

Whisk the dry ingredients: In a separate bowl, combine the flour, baking soda, salt, and cinnamon (if using).

Fold dry into wet: Gradually add the dry ingredients to the wet mixture, stirring just until combined. Overmixing can lead to dense muffins, so a few streaks of flour are fine.

Add mix-ins: If you’re using nuts, chocolate chips, or coconut, gently fold them in now.

Fill the muffin tin: Divide the batter evenly among the muffin cups, filling each about ¾ full.

Bake: Place the tin in the preheated oven and bake for 18-22 minutes, or until a toothpick inserted into the center comes out clean.

Cool: Let the muffins cool in the tin for 5 minutes, then transfer them to a wire rack to cool completely.

Don’t overmix: Overmixing the batter can make the muffins tough. Stir just until everything is combined.

Check for doneness: If the toothpick has a few crumbs, that’s okay—it means your muffins will be extra moist.

Double the batch: These muffins freeze beautifully, so feel free to make extras for later!