Make the blueberry layer: In a small saucepan, combine 1 cup blueberries with 1–2 teaspoons sweetener and 1 teaspoon lemon juice.
Cook over medium heat for 5–7 minutes, stirring, until the berries burst and thicken slightly. Let cool completely.
Blend the cheesecake base: In a bowl or blender, mix 1/2 cup plain Greek yogurt, 2–3 tablespoons softened cream cheese, 1 cup milk, 1–2 tablespoons sweetener, 1 teaspoon vanilla, the zest of 1 lemon, and 1–2 tablespoons lemon juice. Taste and adjust sweetness and lemon.
Add chia seeds: Whisk 1/4 cup chia seeds into the cheesecake mixture.
Stir well to prevent clumps. After 10 minutes, stir again to redistribute the seeds.
Chill: Cover and refrigerate for at least 2–3 hours, but overnight is best. The pudding should be thick and spoonable.
Optional graham crumb: Mix 1/3 cup crushed graham crackers with 1 tablespoon melted butter or coconut oil and a pinch of salt.
Stir until sandy and set aside.
Assemble: Spoon a layer of blueberry compote into a glass. Add a layer of chia cheesecake pudding. Repeat.
Sprinkle with graham crumb and extra lemon zest. Top with fresh blueberries if you like.
Serve: Enjoy chilled. For extra creaminess, add a small dollop of yogurt on top before serving.