Make the cherry layer: Add cherries, lemon juice, and sweetener to a small saucepan over medium heat.
Cook 5–8 minutes, stirring, until the cherries release juice and soften. If you want it thicker, stir in the cornstarch slurry and simmer 1 more minute. Let cool completely.
Whisk the wet ingredients: In a mixing bowl, whisk milk, Greek yogurt, vanilla, lemon juice, and sweetener until smooth.
Add protein powder: Sprinkle in the protein powder and whisk thoroughly.
Aim for a lump-free, creamy base. If it seems too thick, add a splash of milk.
Stir in chia seeds: Add chia and a pinch of salt. Whisk well, then let the mixture sit for 10 minutes.
Whisk again to prevent clumping.
Chill to set: Cover and refrigerate at least 2 hours, or overnight. The pudding will thicken as the chia hydrates.
Layer it: Spoon cherry mixture into jars or bowls, then add the cheesecake chia pudding. You can swirl or layer it neatly—your choice.
Top and serve: Finish with crushed graham crackers for a classic cheesecake vibe, or add almonds for extra crunch and protein.