Preheat the oven to 350 degrees F. Grease three 5" round baking pans and line them with a strip of parchment paper (use this method).

Add the milk, eggs, vanilla and vinegar to a blender or food processor. Blend on high until smooth. Add the oil and quinoa and blend again until smooth.

Whisk together the dry ingredients in a large mixing bowl. Add the contents of the blender into the mixing bowl and stir together until the batter is smooth. Set aside and let rest for 5 minutes.

Evenly divide the batter between the three baking pans. Bake on the center rack for 25 - 28 minutes until a cake tester inserted into the center comes out clean.

Remove the cakes and let cool in the pan for 10 minutes then turn them out onto a wire rack and cool completely.

While the cakes are cooling, prepare the frosting. Add the sweet potato, maple syrup and coconut oil into a food processor and process until smooth. Add remaining ingredients and process until incorporated and smooth. Taste and add stevia as needed.

Transfer the frosting to a bowl and place in the fridge until cakes are cooled.

When cakes are completely cool, frost and sprinkle with chocolate chips.