Start by preheating the oven to 375 F and lining a 9×5 loaf pan with parchment paper (you can spray the inside of the pan first so the paper sticks to it).
In a large bowl, whisk together the wet ingredients: apple sauce, melted butter, vanilla extract, maple syrup, and oat milk.
Next, fold in the dry ingredients: oat flour, oats, cinnamon, nutmeg, baking soda, baking powder, and salt.
Stir until just combined, and then pour the mixture into your loaf pan.
Bake for 35-40 minutes, or until the top is lightly browned and a toothpick comes out clean.
While the loaf is baking, prepare the frosting.
In a mеdіum bоwl, mіx together thе роwdеrеd ѕugаr, mарlе ѕуruр, melted butter, аnd oat mіlk. If the frosting is too thick, you can thin it out by adding more milk, one teaspoon at a time.
Once the loaf is COMPLETELY cooled, spread the frosting evenly on top. If your loaf isn’t completely cooled, the frosting will melt, so make sure it’s not hot!
Sprinkle with an extra dash of cinnamon on top, slice, and enjoy!