HEALTHY BLUEBERRY MUFFINS 1,5 big bananas , 1 egg 1,5 cup oatmeal 2 tbs cinnamon 2 teaspoons of baking soda blueberries -First you pre heat the oven at 200 degrees (Celsius). Then: -Mix the bananas and the egg in a blender until it’s completely smooth. -Now add the baking soda and the cinnamon and blend again. Pour everything into a bowl and add the oatmeal and blueberries and stir a little with a spoon. - Divide the batter across the muffin cups and put it in the oven for 20 minutes.