Heat the oven to 350 degrees Fahrenheit and spray your mini muffin tin or standard muffin tin with non-stick cooking spray (you can also line with paper liners if you wish) . In a large bowl, stir together the flour, oats, brown sugar, flaxseed, baking soda, baking powder and cinnamon. Add the egg, oil, yogurt and water. Mix until the dry and wet ingredients are just combined, the mixture will be thick. Spoon the batter into the muffins cups, filling each cup right up to the top, and bake for 12-15 minutes, until a toothpick inserted into the center comes out clean. Cool in the pans for 5 minutes, then turn out onto a rack and cool completely before serving.