Preheat the oven to 350℉/175℃ and line a mini muffin pan with small liners.
In a half sheet pan or in a baking dish, pour out the oats on the pan so they make an even layer. Bake in the oven for 6-8 minutes, or until lightly toasted. Remove from the oven and let cool. Keep the oven at the same temperature.
In a large bowl, mash the bananas with a fork or potato masher. Add the egg, sour cream, light brown sugar, melted butter and vanilla extract. Whisk until almost smooth - you will have some lumps because of the bananas!
In another medium, whisk the toasted oats with the flour, baking powder, baking soda, spices and salt.
Pour the dry ingredients into the wet ingredients and fold everything together with a rubber spatula until there are no more streaks of flour.
Scoop out the muffin batter into the prepared pan. I like using a small cookie scoop for this. Fill each cavity to the top! This makes 30 muffins and most mini muffin pans come as 24, so you may need to bake them in two batches.
Bake the muffins for 12-14 minutes.
Notes
My recipes have been developed and tested in cups and metric grams. I highly recommend using a weighing scale and measuring out your ingredients the metric way. Just click on ‘METRIC’ above the ingredients. Butter: I use European style butter in my recipes. This will make your finished bake much creamier and richer.Salt: If you don’t have kosher salt, halve the amount of salt called for in the recipe. 1 teaspoon kosher salt = ½ teaspoon fine salt. Please note I am using Diamond Crystal kosher salt and not coarse kosher salt (like Morton salt) which is far too salty for this recipe. Muffin Pan:This is the muffin pan I used. Regular Sized Muffins: You can make these in a regular muffin pan if you wish! It will make 12 muffins, just bake in the oven for 25-30 minutes. Storage: keep the mini banana muffins in an airtight container in the fridge for up to 4 days.