Whisk the base: In a medium bowl, whisk Greek yogurt, milk, protein powder, lemon juice, lemon zest, vanilla, sweetener, and a pinch of salt until smooth. If using cream cheese, whisk it in here until no lumps remain.
Add chia seeds: Stir in the chia seeds until evenly distributed.
Let the mixture sit for 5 minutes, then stir again to prevent clumping.
Adjust sweetness and lemon: Taste and adjust lemon juice or sweetener. The flavors will mellow slightly as it chills, so aim for a bright, slightly tangy taste.
Chill to thicken: Cover and refrigerate for at least 2 hours, ideally overnight. The chia seeds will hydrate and the pudding will set to a creamy, spoonable texture.
Stir and serve: Give it a good stir before serving.
If it’s too thick, loosen with a splash of milk. If too thin, stir in another teaspoon of chia and chill 10–15 minutes more.
Add toppings: Finish with berries, a sprinkle of crushed grahams for that “crust” feel, and a touch of zest for aroma.