Preheat your oven to 350 degrees F.
Whisk together the first 7 dry ingredients.
Make 3 depressions or shallow dips in the dry mixture, 2 small and 1 large.
Pour the vinegar in a small depression, the vanilla extract and chocolate stevia in the other small depression and the oil in the large depression.
Pour the water over the top and stir until smooth.
Spread the batter into the baking pan.
Place in the middle rack of your oven and bake for 30 minutes or until a toothpick in the center comes clean.
Allow to cool for 10 minutes then remove by holding the ends of the parchment paper.
Place onto a cutting board to frost then slice.