To prepare, preheat your oven to 425 and spray a muffin mold with cooking oil or fill with parchment liners.
Meanwhile, in a large bowl, combine the wet ingredients (beet, egg, coconut oil) and mix thoroughly with a spoon.
In a separate bowl, add each of the dry ingredients (oats through baking soda) and toss to combine.
Transfer the dry mixture into the wet mixture slowly, stirring with a spoon to mix as you go.
Add the remaining ingredients and spices, stirring to combine. Don't worry if your batter appears to be runny at this stage, they will bake up into dense decadent muffins.
Evenly distribute the batter among (6) muffin molds.
Bake for about 25 minutes, or until the tops of the muffins round (they will not fully rise, these have more of a dense cake texture) and a tooth pick pulls out clean.
Allow to cool slightly (3-5 minutes, to prevent residual cooking) and remove from the muffin mold.
If you're ready to eat, top each muffin with the frosting mixture! If you're saving some for later, store them in an airtight container for up to 6 days.