Preheat oven to 350°F.
Sift together ingredients (flour, powdered chocolate, sugar, baking soda, salt) into a large bowl.
In a separate bowl, blend wet ingredients together (water, grapeseed oil, balsamic vinegar, and vanilla).
Slowly blend the dry ingredients into the wet ingredients.
Bake for 1 hour.
Serve alone or glaze with chocolate glaze, frosting, or powdered sugar.