Pour the rolled oats into a mason jar or container with a lid, then add the milk. Stir well to combine, making sure all the oats are moistened and there are no dry pockets at the bottom. I like to use whole milk because it creates a creamier texture overnight, but any milk works well here—dairy or non-dairy. The oats will absorb the liquid as they sit, so don't worry if the mixture seems a bit loose at this stage.

Cover the container with a lid and place it in the refrigerator for at least 6 hours, though overnight (8-12 hours) is ideal. During this time, the oats will soften and absorb all the milk, transforming into a creamy, pudding-like breakfast. I find that letting it sit overnight creates the best texture—the oats become tender without becoming mushy, and the flavors meld together nicely.

Remove the container from the refrigerator and give it a quick stir, adding a splash more milk if you prefer a looser consistency. Transfer to a bowl or eat directly from the jar, then customize with your favorite sweeteners (honey, maple syrup, or brown sugar) and toppings (fresh berries, nuts, granola, coconut flakes, or a drizzle of nut butter). The overnight oats are ready to eat as-is or can be gently warmed in the microwave if you prefer them warm.