1. Preheat oven to 350°F. Grease a 9×13-inch baking pan. Wash hands with soap and water.

2. In a large bowl, combine the flours, cocoa, baking soda, and salt.

3. In a large blender or food processor, puree beets until smooth. Add sugar, oil, eggs, and vanilla. Puree until ingredients are well combined and mixture is smooth, about 1 minute. Or carefully combine with an electric hand mixer.

4. Pour beet mixture over flour mixture. Combine ingredients with a spoon or whisk until just smooth. (Batter will appear red, but will turn chocolate brown when cooked.)

5. Pour batter into a greased 13×9-inch baking pan. Bake 25-30 minutes or until a toothpick inserted in the center comes out clean.

6. Cool completely before serving.

Note:
Using fresh beets (roasting): Preheat oven to 400°F. Use around 1 pound of beets. Cut off leaves and stems, leaving about 1/2-inch of stem on beets. Rinse beets under cool water, rubbing with fingers to remove any soil. Dry with a paper towel. Add beets to an oven-safe baking dish with a lid. Add enough oil to lightly coat the beets, stirring to coat. Roast for 45 minutes or until a knife easily pierces a beet. Let cool 5 minutes. Using clean hands, rub skins off beets. Cut into pieces and puree until smooth. Measure out 2 cups.