Make the coffee base. Brew strong coffee or use cold brew. Let it cool completely. Cold coffee prevents the oats from getting mushy and keeps dairy from curdling.

Stir the oat mixture. In a jar or bowl, combine rolled oats, chia seeds, a pinch of salt, milk, and 1/3 cup of coffee. Mix well so the chia doesn’t clump.

Add sweetness and flavor. Stir in maple syrup (or honey) and vanilla. Taste the liquid; it should be slightly sweeter than you think because the oats will absorb and mellow it.

Create the “cream” layer. In a separate small bowl, mix Greek yogurt with mascarpone (if using) until smooth. Sweeten lightly with a drizzle of syrup. You want it creamy but not overly sweet.

Layer like tiramisu. Spoon half the oat mixture into your jar. Dust lightly with cocoa powder. Add a few crumbs of biscuit or granola if you want crunch. Spread half of the yogurt cream on top.

Repeat. Add the remaining oats, another cocoa dusting, and finish with the rest of the yogurt cream. Smooth the top.

Chill overnight. Cover and refrigerate 6–12 hours. The oats will soften, and the flavors will settle into that tiramisu groove.

Top and serve. In the morning, add a final cocoa dusting and a sprinkle of dark chocolate shavings or cacao nibs. If it’s too thick, loosen with a splash of milk or coffee.