In a large mixing bowl, combine rolled oats, chia seeds, and cocoa powder. Stir thoroughly until fully blended.

Add Greek yogurt and maple syrup to the dry mix. Mix well to ensure even incorporation.

Pour in milk gradually while stirring, then add vanilla extract and a pinch of salt. Continue mixing until smooth.

Fold in chocolate chips if desired, taking care not to break them apart too much.

Transfer to a jar or airtight container, seal tightly, and refrigerate for at least 6 hours or overnight.

In the morning, stir the mixture, adding milk if too thick. Top with chocolate chips or fresh fruit before serving.