Combine the mashed bananas and brown sugar. Next, add in the buttermilk, oil, eggs. In a separate large bowl mix the flour, oats, baking powder, baking soda, salt, cinnamon, nutmeg, flaxseed and turmeric. Mix the wet and dry ingredients. Fill greased muffin tins 3/4 full, and then bake for 18-20 minutes, or until golden brown, at 400.