Dissolve 2 tablespoons of instant espresso powder in 1/2 cup of hot water until fully dissolved.

In a mixing bowl, combine 1 cup of milk, 1 teaspoon of vanilla extract, and 2 tablespoons of cocoa powder. Whisk until smooth.

In a clean jar, add 1 cup of old-fashioned rolled oats, 1 cup of Greek yogurt, and optional 1 tablespoon of chia seeds. Pour in the liquid mixture and sprinkle in a pinch of salt, stirring until well combined.

Seal the jar and refrigerate for at least 4 hours, preferably overnight.

Stir the mixture before serving and add extra milk for desired consistency. Top with dark chocolate shavings or cocoa powder.