Add the Greek yogurt, blueberries, sweetener, milk, protein powder, vanilla, lemon zest, lemon juice, and salt to a large bowl. Stir until well combined.

Fold in the rolled oats and chia seeds until evenly mixed. If the mixture feels too thick, add a small splash of milk.

Divide the oat mixture evenly between 4 containers.

In a blender or food processor, blend the 200 g Greek yogurt, 100 g cottage cheese, sweetener, vanilla, pinch of salt, and lemon zest until smooth and creamy.

Spoon the cheesecake topping evenly over each portion of oats.

Cover and refrigerate overnight, or for at least 4 hours, until the oats and chia seeds have softened and thickened.