Preheat your oven to 325°F (160°C). Line the bottom of a 9-inch springform pan with parchment paper.

Combine almond flour, cocoa powder, melted butter, and erythritol in a medium bowl until blended. Press firmly into the bottom of the pan. Bake for 10 minutes and let cool.

Beat softened cream cheese in a large bowl until smooth. Add powdered erythritol and mix well. Add eggs one at a time, mixing in between. Stir in sour cream, vanilla extract, and lemon zest.

Pour the filling over the cooled crust and bake for 50-60 minutes until set around the edges. Let cool inside the oven for 1 hour.

Refrigerate for at least 4 hours or overnight.

Combine blueberries, water, lemon juice, and sweetener in a saucepan. Cook over medium heat until blueberries burst. Thicken with cornstarch slurry and cook until thick.

Cool the topping mixture to room temperature.

Spread the cooled blueberry topping over the cheesecake. Optionally sprinkle with edible silver.

Slice and serve, optionally with whipped cream or mint garnish.