Dissolve instant espresso powder in hot water and let cool slightly. Alternatively, use cold brew coffee.

In a medium bowl, whisk together milk, vanilla extract, cocoa powder, and sweetener until smooth.

In a larger jar or bowl, combine oats, Greek yogurt, chia seeds, and protein powder. Add a pinch of salt and stir well.

Pour cooled coffee base into the oats mixture, stirring until everything is evenly coated.

Seal jar or cover bowl and refrigerate for at least 4 hours, ideally overnight.

Before serving, stir the mixture. Add milk if too thick and consider topping with dark chocolate shavings or cinnamon.