Start by processing the cooked beets into a smooth puree. Make sure that there are no little chunks of beets left. Scrape the sides and process until very very smooth.
Preheat the oven to 350°F. Lightly grease a 8" round pan that is at least 2" deep. Line the bottom of the pan with parchment and spray it with cooking spray.
In a large mixing bowl, combine flour, sugar, cocoa powder, baking soda, salt and egg replacer powder.
Stir in canola oil, warm almond milk (or warm water), pureed beets and vanilla. Mix well until combined.
Pour the batter into the prepared pan and bake for 40~45 minutes or until a toothpick inserted into the center of the cake comes out clean.
Let the cake cool for 15~20 minutes in the pan before turning it out onto a wire rack to cool completely.