Preheat oven to 375°F (190°C).
Mix together the first eight (dry) ingredients, then combine with the yogurt, cooled melted butter, and egg to make a batter.
Divide into 12 paper lined muffin cups.
Bake in the preheated oven for 20-22 minutes or until a toothpick, inserted, is removed without wet batter clinging to it.
Turn muffins out of pan and cool on a wire rack.