In a small bowl, melt 1 tablespoon of dark chocolate in the microwave in 20-second increments, stirring until smooth. Let it cool slightly while you prepare the other ingredients. Personally, I find melting chocolate gently prevents it from seizing and gives a silkier texture.

In a mason jar or airtight container, combine the old-fashioned oats, milk, Greek yogurt, chia seeds, unsweetened cocoa powder, pure vanilla extract, maple syrup or honey, and the melted dark chocolate from Step 1. Stir the mixture well to ensure all ingredients are evenly distributed and the chocolate is well incorporated.

Stir 1 tablespoon of semisweet chocolate chips into the oat mixture to heighten the chocolatey flavor and provide delightful chocolate morsels throughout.

Seal the jar or container and place it in the refrigerator. Let it chill and soak overnight, or at least 4 hours, so the oats absorb the liquid and the mixture becomes creamy and thick.

Before serving, optionally drizzle additional melted chocolate, sprinkle extra chocolate chips, and dust with cocoa powder for an indulgent finish. I like to add a little extra cocoa powder on top—it enhances the chocolate flavor and looks beautiful too.