For the cake, preheat the oven to 350˚F. Lightly grease two 8-inch cake pans and line the bottoms with parchment paper.
In a Vitamix or blender, combine the milk, eggs, vanilla, coffee liqueur and coconut oil. Blend until incorporated. Add the quinoa, sugar, cacao powder, baking powder, baking soda and salt. Blend, increasing the speed to high, until smooth, stopping and scraping occasionally.
Divide the batter between the prepared pans and spread in an even layer. Bake 20-23 minutes, or until the cake springs back when lightly pressed and a toothpick inserted in the center comes out mostly clean with a few crumbles (don’t over-bake otherwise the cake will be dry). Let the cakes cool in the pans set on a wire rack for 10 minutes. Invert the cakes onto racks, and peel off the parchment. Let cool completely before frosting.
For the cocoa whipped cream frosting, place all of the ingredients in a clean Vitamix (if you don't have a Vitamix, you can make the frosting in a bowl using a stand mixer or electric mixers instead). Blend on low until fully incorporated. Slowly increase the speed, blending until the mixture is thickened (it will no longer move around the blade in the Vitamix). If using the Vitamix, stir with the tamper while the machine is running until the cream is stiff—it will only take a few more seconds (if using a bowl and mixers, simply continue beating until stiff).
To frost the cake, very carefully slide one of the cake layers onto a cake stand or serving platter (the cake is very tender and has a tendency to break if it’s handled too much, so go slowly! That being said, if it does break, simply patch it back together on the cake plate—nobody will know!). Spoon about a quarter of the frosting on top, and spread it in an even layer. Place the second cake layer over top, and spoon on the remaining frosting. Spread the frosting in an even layer on top and around the sides of the cake. If possible, cover the cake with a dome or large bowl and refrigerate it for at least 1 hour before serving.