Preheat oven to 325°F (160°C). Line a 12-cup muffin tin with paper or silicone liners.

In a medium bowl, combine the graham cracker crumbs, melted butter (or coconut oil), and 1 tbsp granulated erythritol. Mix until well combined and resembles wet sand.

Divide the crumb mixture evenly among the 12 muffin liners, pressing firmly into the bottom to form the crust. Bake for 5 minutes, then remove from oven and let cool slightly while preparing the filling.

In a large mixing bowl, beat the softened light cream cheese with a hand mixer or stand mixer on medium speed until smooth and creamy, about 2-3 minutes.

Add the plain Greek yogurt, 1/2 cup granulated erythritol, lemon zest, lemon juice, and vanilla extract. Beat until just combined, scraping down the sides of the bowl as needed. Do not overmix.

Add the large egg and beat on low speed until just incorporated. Be careful not to incorporate too much air, which can cause cracks.

Gently fold in the fresh blueberries by hand with a spatula.

Pour the cheesecake filling evenly over the pre-baked crusts in the muffin tin, filling each liner about 3/4 full.

Bake for 15-20 minutes, or until the edges are set but the centers still have a slight jiggle. Do not overbake.

Turn off the oven, prop the oven door open slightly, and let the cheesecakes cool in the oven for 30 minutes. This helps prevent cracking.

Remove the cheesecakes from the oven and let them cool completely on a wire rack at room temperature.

Once cooled, transfer the muffin tin to the refrigerator and chill the mini cheesecakes for at least 4 hours, or preferably overnight, before serving.