The best banana cupcakes with an amazing cream cheese frosting
Preheat oven to 350 degrees F. Line a 12-cavity muffin pan with cupcake liners and set aside. In a medium-sized bowl, whisk together the flour, baking soda, baking powder, salt, cinnamon, and nutmeg. Set aside.
In a separate large mixing bowl, using hand mixers, beat together the butter, brown sugar, and white sugar until smooth and creamy. Mash over-ripe bananas and measure to make sure you have exactly 3/4 cup. Beat in the bananas to the batter until smooth. Add in the full egg, egg yolk (reserve whites for another recipe/omeletes throughout the week or discard), and pure vanilla extract. Beat until smooth.
Add the dry to the wet ingredients alternating additions with the buttermilk (Add half the dry, half the buttermilk, rest of the dry, rest of the buttermilk). Beat after each addition JUST until the ingredients are incorporated being careful to not overmix.
Pour batter into the prepared muffin cups, filling each cup about 3/4 full. You should use all of the batter between 16 cavities. Bake in preheated oven about 18 - 22 minutes or until a toothpick when inserted into center of cupcake comes out clean. Cool in muffin tin several minutes then transfer to a wire rack and cool completely.
Meanwhile, prepare the frosting. Using a hand mixer, cream together the room temperature butter and cream cheese on medium-high speed until completely smooth. Mix in vanilla extract, sea salt and cinnamon. With mixer running on low speed, slowly add powdered sugar and beat until well blended and smooth. Chill the frosting while the cupcakes finish cooling.
Frost completely cooled cupcakes with cream cheese frosting and if desired, garnish with a banana chip.
You can make your own buttermilk by combining 3/4 cup milk with 3/4 of 1 full tablespoon vinegar or lemon juice. Stir and set aside for 5 minutes before using. Do not use plain milk for this recipe.