Prep the pan: Line a mini muffin pan (24-count) with paper liners or use silicone cups. Preheat oven to 325°F (163°C).
Make the crust: In a bowl, mix 1 cup almond flour, 2 tablespoons erythritol, a pinch of salt, and a pinch of cinnamon. Stir in 3 tablespoons melted butter until the mixture resembles damp sand.
Press and pre-bake: Spoon about 1 teaspoon of crust mixture into each cup.
Press down firmly with the back of a spoon. Bake 6–7 minutes until lightly golden. Set aside to cool slightly.
Beat the filling: In a mixing bowl, beat 8 ounces softened cream cheese until smooth.
Add 1/3 cup erythritol, 1/4 cup sour cream, 1 large egg, 1 teaspoon vanilla, 1/2 teaspoon lemon zest, and a tiny pinch of salt. Beat just until smooth and combined. Do not overmix.
Fold in blueberries: Gently fold in 1/2 cup blueberries.
If using frozen, sprinkle them with a teaspoon of almond flour first so they don’t bleed as much.
Fill the cups: Divide the filling among the crusts, filling nearly to the top. Tap the pan lightly to settle.
Bake: Bake at 325°F (163°C) for 12–16 minutes, until the edges are set and the centers still wobble slightly. They will firm up as they cool.
Cool and chill: Let the bites cool in the pan for 20 minutes.
Transfer to the fridge and chill at least 1–2 hours before serving for the best texture.
Serve: Enjoy as-is or top with a couple of extra blueberries and a light dusting of powdered erythritol.