Preheat the oven to 375 degrees. Prepare your muffin tin by spraying with nonstick spray or by placing muffin liners in each spot.
First, wet ingredients. In a large mixing bowl, add your eggs, sugar, brown sugar, salt and butter and whisk until all is combined and creamed together. (You can also use a stand mixer, but I dont find it necessary.
Mash your bananas. Add your mashed bananas to the bowl. Next add the sourdough discard and milk and continue to mix all until it is completely combined.
Next Your dry ingredients. Add your flour, baking powder and baking soda. Fold in until just combined. Do not overmix. Add your chocolate chips if you like those.
If you want to add a streusel topping, mix the melted butter, sugars and flour together until it combined and becomes crumbly.
Scoop 2-3 tablespoons of batter into each muffin liner. Top with streusel or cream cheese for an added treat. I like to use my cookie scoop, or you could also use an ice cream scoop.
Place in the oven and bake for 20-22 minutes.
Remove from oven and let cool for at least 30 minutes before eating. I like to cool them on a cooling rack.
Store in an airtight container on your counter or freeze for up to 3 months. You can also keep them in the fridge if you choose.