In a medium sauce pan combine blueberries and water. Heat over medium high heat until boiling and then reduce heat to medium. Stir occasionally and cook for about 5 minutes until saucy and most of the blueberries have burst. Remove from heat, put in a bowl and let cool in fridge.

Preheat oven to 350 degrees F with the rack in the middle. Prepare an 8 x 2″ round cake pan with parchment paper. Toss 1 cup of fresh blueberries with the tablespoon of corn flour, set aside. In a medium bowl whisk together dry ingredients. In another bowl mix together egg, vanilla, butter, sour cream, and 1 cup of the blueberry sauce. Combine the ingredients from both bowls, add stevia powder and taste batter to see if it is sweetened to your liking. Gently fold in fresh blueberries.

Put batter in pan and bake for about 30 minutes, until a toothpick comes out clean. Let cool and carefully flip out of pan onto a plate.

Combine whipped cream cheese with 1/4 cup cooled blueberry sauce. Add stevia or your favorite natural sweetener to taste.

Flip cake from pan onto a plate when cooled to room temperature. Cut cake in half horizontally with a long serrated knife. Frost bottom layer with 1/2 of the frosting and some of the blueberry sauce. Top with the second cake layer. Add some more cream cheese frosting and decorate with fresh blueberries, and piped cream cheese frosting. Serve with extra blueberry drizzled over the top and on the side in a pitcher.