Start by making the beet puree. Peel and chop all the beets and place them in a sauce pot filled with water. Boil until fork tender, then blend while beets are still warm. You may add some of the boiled water in to make a smooth puree. Set aside 2 Tablespoons for the glaze, and the rest should be about a cup for the cake.
Next, preheat oven to 350 degrees F (176 C). Cut a piece of parchment the size of your cake pan, and spray baking spray around the bottom and edges. Place parchment over the bottom and spray again.
Sift together cocoa powder, flour, baking soda, and salt. Set aside.
In a standing mixer fitted with a paddle attachment, mix oil and sugar. Add eggs. Next, alternately add flour mixture and warm water until smooth. Lastly, add beet puree and vanilla.
Pour mixture into prepared cake pan. Bake in the center of the oven for 50-55 minutes or until a toothpick comes out clean. The cake will dome up not spill over.
When cake is out of the oven, start the glaze. Sift the powdered sugar into a medium size bowl, add the beet puree, corn syrup, and water and whisk until smooth.
Place cake on a rack to glaze or just glaze while on a cake plate.
You can keep this cake out for a week and it won’t dry out. ENJOY!