Stir together the oats, milk, grated carrots, chia seeds, maple syrup, cinnamon, nutmeg, vanilla, and raisins in a big bowl. The mixture will look colorful and smell sweetly spicy.

Divide this oat mixture among four wide jars or containers (mason jars work wonderfully).

In a separate bowl, mix the Greek yogurt with the softened cream cheese until totally smooth and creamy—no lumps.

Spoon this cheesecake-like yogurt topping over the oats in each jar, spreading gently to cover.

Cover each jar tightly and refrigerate. The oats and chia seeds will soften and thicken, while the layers set up beautifully.

Right before serving, sprinkle each jar with chopped walnuts for crunch.

If you like, give the oats a quick stir to swirl all the flavors, or keep the layers distinct for that bakery look when serving.