Grate the beets until you have about 2 cups (not packed tightly together). Place a colander inside a large mixing bowl, and pour grated beets into the colander. Let them naturally drain of any excess moisture - don't wring them out or use paper towels to sop up liquid! You want them to retain a moderate amount of moisture.
Preheat the oven to 350F. Spray two 9" round cake pans with nonstick spray and dust them lightly with cocoa powder. Set aside.
In a large mixing bowl, whisk together the butter, oil, sugars, and maple syrup/honey until thoroughly combined.
Add eggs and vanilla and stir to combine.
In a separate large bowl, whisk together flour, cocoa powder, baking soda and salt.
Slowly add dry ingredients to wet ingredients and stir to combine.
Add beets and stir to combine.
Pour batter into prepared cake pans and use a spatula to even out the top if needed.
Bake each cake (one at a time) for 25 minutes or until a toothpick inserted into the center of the cake comes out with a few moist crumbs. Let cool in pan for 15-30 minutes, or until you feel comfortable touching the pan without oven mitts. Run a knife or thin spatula around the edges to loosen the cake from the pan, then carefully invert the cake pan onto a wire rack and let the cake cool completely.
Use a serrated knife to slice a thin later off the top of each cake so that they're flat and ready to be stacked.
Place the first cake layer on your serving platter/cake stand and cover with your frosting of choice. Top with the second cake later and frost that as well. If you want you can cover the sides of the cake as well, or just leave them naked!
Decorate as desired, slice and enjoy!