Preheat oven to 325°F and line an 8×8-inch pan.
Mix crust ingredients, press into pan, bake 8–10 minutes.
Cook blueberries, sweetener, and lemon juice until thick.
Beat cream cheese, add eggs, sweetener, sour cream, lemon juice, zest, vanilla.
Pour batter, swirl blueberry sauce.
Bake 25–30 minutes, chill 3 hours.