Preheat the oven to 400 degrees Fahrenheit.

Scrape off the beet skins (they should peel off easily) and chop into chunks. Add the beet chunks to a food processor and purée until completely smooth.

Preheat the oven to 350 degrees Fahrenheit and spray two 8" cake pans with cooking spray.

In a stand mixer bowl with whisk attachment, add the beet puree, almond milk, melted coconut oil, vanilla, butter flavor, and stevia extract.  Mix on low speed.

In a medium-sized bowl, whisk together the oat flour, sorghum flour, erythritol, starch, cocoa powder, baking powder, and salt.  Dump the dry ingredients into the stand mixer and mix on medium speed until fully incorporated.  Scrape down the sides of the bowl, then return to medium speed.

Add the vinegar in LAST.  Moving quickly now, pour the batter into the prepared pans and place them in the oven. Bake for 27-31 minutes, or until the surface of the cakes spring back when tapped.  Let the cakes cool in the pan.

Drain the package of tofu and place the tofu block on paper towels.  Press as much liquid out of the tofu as possible.

Place the tofu, coconut milk, vanilla, powdered erythritol, and salt in a food processor or high-speed blender. Puree until completely smooth.

Scrape down the sides of the processor or blender.  While blending, pour in the melted chocolate.  Blend until fully incorporated.  Pour the mixture into a large bowl.  Cover with plastic wrap and refrigerate for 4+ hours or overnight.  Frost the cake, then refrigerate for 30 minutes to an hour to set up.  Slice and serve!