Pre-heat the oven to 375 degrees.
Combine oat flour, baking powder, baking soda, coconut sugar, salt, cocoa, and coffee grounds in a large bowl. Mix to combine.
Combine honey, maple syrup, coconut milk, coconut oil, egg, vanilla extract, and greek yogurt in a medium bowl. Whisk to combine.
Add wet ingredients to the dry ingredients, stir to combine until you don't see any flour spots.
Spray the donut pan with baking spray. Pour the batter into each cavity ¾ full.
Bake for 15-17 minutes, or until a toothpick comes out clean. Remove donuts from the tray, place on a wire rack to cool completely.
Mix all ingredients for the glaze in a bowl. Dip each donut into the glaze and put back on the rack.
Put M&M’s® into a Ziploc bag, and break them up using the back of a spoon. Sprinkle the crumble over the top of each donut.