Combine rolled oats, chia seeds, and unsweetened cocoa powder in a mixing bowl. Stir using a whisk or fork until evenly blended, about 30 seconds.

Add the plain Greek yogurt and maple syrup to the dry mixture. Mix well for about 1 minute until fully combined, achieving a thick, creamy texture.

Pour in your choice of milk, then stir in the vanilla extract and a pinch of salt. Mix until smooth and uniform.

If using, gently fold in chocolate chips until evenly distributed.

Spoon the mixture into a sealed jar or airtight container, cover tightly, and place it in the refrigerator for at least 6–8 hours or overnight.

In the morning, stir the oats and add a splash of milk if too thick. Serve with chocolate chips, peanut butter drizzle, or fresh berries.