Blend all dry ingredients together in a large bowl or measuring cup.
Mix the mashed banana, sugar, milk, vanilla, oil and egg.
Combine the two mixtures until just moistened – don’t over-mix.
Using 2 spoons, drop into 12 lightly greased muffin tins.
Bake at 350°F (175°C) for 18 to 20 minutes.
Makes 1 dozen muffins.