This is a not-too-sweet version.
1 cup quick oats
1 cup buttermilk
0.25 cup brown sugar
2 tbs white sugar
0.25 cup vegetable oil
1 cup flour
1 tsp baking powder
0.5 tsp baking soda
0.25 tsp salt
1 tsp cinnamon
1 tsp vanilla
0.25 cup flax seeds (optional)
Heat the oats in the buttermilk and allow to soak for 10 minutes.
Stir in beaten egg, sugar, vanilla and oil.
Combine flour, baking powder, baking soda, cinnamon and salt. Fold into oat mixture.
Grind the flax seeds and mix into the batter. Add the peeled and diced apple.
Scoop into 10 paper-lined muffin cups. Bake at 400F for ~15 minutes, or until muffins test done.
Cool in shape for 5 minutes, then transfer onto cookie rack to cool completely. Freeze if desired.