Preheat oven to 375°F. Line a 12 cup muffin tin.
In a large bowl, mix the dry ingredients together (oats, flours, baking powder, baking soda, salt, cinnamon and sugar).
In a smaller, separate bowl, beat together the remaining ingredients (except the chocolate chips and/or fruit).
Pour the wet ingredients into the dry and stir until half mixed. Stir in the chocolate chips until just blended.
Divide the batter equally between the cups until full to the top. Bake for 20-25 minutes.
Cool on wire rack in tin for 5-10 minutes, then remove from tin to finish cooling on wire rack.
Store in an airtight container for up to three days or frozen for up to three months.