In a small bowl, mash the raspberries with the back of a fork until broken down and jammy. Stir in the chia seeds and honey until well combined. Set aside (or refrigerate if making ahead).
Prepare your base recipe as directed and pour half into a jar or airtight container. Spoon the raspberry chia jam directly on top of the oats, right in the center, without stirring. Top with the remaining half of your base recipe. Cover and refrigerate overnight, or for at least 6 hours.
In the morning, dig your spoon down through the chia jam and swirl it into the oats as you eat — or stir everything together for a fully mixed, raspberry-swirled bowl. Top with fresh raspberries and an extra drizzle of honey.