In a food processor, blend the oat into a flour. You can buy oat flour and use it too.
Melt the coconut oil in a bowl, then mix in sugar, salt, eggs, mashed bananas, honey, vanilla extract and oat flour. Mix to combine.
Mix whole wheat flour, baking powder and cinnamon powder together, then add to the batter. Mix to combine.
Mix chopped walnuts or chocolate chips if you like. You can also arrange on top.
Divide the batter into the muffin cups or your favorite molds. Bake it in a preheated oven at 200°C/390℉ for 8 min, then turn down to 180°C/360℉ and bake it another 15 min.