In a medium sized bowl whisk together the yogurt, milk, vanilla and lemon zest until combined.
Whisk in the protein powder, chia seeds and pinch of salt. Stir in the oats until combined.
Take two jars and spoon 1/4 of the mixture into each one.
Spoon 1/4 of the blueberries into each jar, then repeat the process ending with the blueberries on top. Cover the jars with lids and refrigerate overnight.
Notes
If you don't want to use protein powder, substitute with 2 tablespoons (or to taste) of honey or maple syrup.