Preheat oven to 375 degrees. Line 12 muffin cups with muffin liners and set aside.

In a bowl, whisk together the banana, egg, sour cream, oil, milk, and vanilla.

Add in the flour and sugar. Then top the four and sugar with the soda and salt. Use a fork and gently mix the soda and salt into the flour without mixing it in the liquid yet. Once that is mixed well into the flour, whisk the dry ingredients into the wet until smooth.

Divide batter evenly between the 12 lined muffin cups.

Bake at 375 degrees for 20 minutes until the tops spring back when lightly touched and are a deep golden brown color.

Serve warm or cool completely. Serves 12.