In a small saucepan over medium heat, combine blueberries and water. Bring to a boil and then simmer 5 to 7 minutes. Remove from heat and sprinkle with xanthan gum, whisking vigorously to combine. Let cool.
Cream Cheese Filling:
In a medium bowl, beat cream cheese until smooth. Beat in egg until well combined, then beat in Swerve and stevia.
Cake:
Preheat oven to 350F and grease a 9-inch springform pan.
In a medium bowl, whisk together almond flour, sweetener, vanilla protein powder, baking powder, xanthan gum, baking soda and salt.
In a large bowl, beat yogurt and butter together until smooth. Add eggs one at a time, beating lightly after each addition, then beat in stevia extract.
Beat in almond flour mixture in two additions, alternating with almond milk and scraping down beaters and sides of bowl as needed.
Spread batter in well-greased 9-inch springform pan with removable bottom, pushing batter up sides of pan to create center well for filling. Sides should be about 1 inch wide.
Spread cream cheese mixture evenly into center well, and then spread blueberry mixture over top of cream cheese.
Bake in 350F oven 30 to 35 minutes, or until sides are set. Center will still jiggle somewhat.
Let cool in pan. Run a sharp knife around cake in pan to loosen, and remove sides. Cover tightly with plastic wrap and refrigerate for at least one hour. Keep refrigerated.