Preheat the oven to 350 degrees Fahrenheit and line a muffin pan with paper liners.

Transfer the rolled oats to a high-powered blender and blend for 1 minute, or until a flour forms. Add the cocoa powder, baking soda, sea salt, and cinnamon to the blender and blend for 10-30 more seconds or until all of the dry ingredients are well-combined.

Mash the bananas in a large mixing bowl until they reach your desired texture. You can mash out all the lumps or leave them somewhat lumpy which is what I do.

Pour the dry ingredients into the bowl with the wet ingredients and mix well, until a thick batter forms. If adding, stir in the chocolate chips.

Pour muffin batter into the lined muffin tin, filling the muffin cups most of the way up. If you'd like, top the muffin batter with extra chocolate chips.

Bake on the center rack of the preheated oven for 20-30 minutes, or until the muffins test clean. A great way of checking whether or not muffins are cooked through is to take their internal temperature using a digital thermometer (or meat thermometer). Simply insert a thermometer into the center of a muffin and if it is higher than 190 degrees Fahrenheit, it is baked through.

Allow the muffins to cool to room temperature before peeling off the muffin papers to enjoy.