In a mason jar or container, add the rolled oats, almond milk, cottage cheese, honey, vanilla extract, and ground cinnamon. Stir everything together until well combined and the cottage cheese is evenly distributed throughout the mixture. The honey will help bind the ingredients and add natural sweetness. I like to use a fork to gently break up any clumps of cottage cheese so the texture stays creamy rather than lumpy.
Fold in the fresh or frozen berries into the mixture from Step 1, reserving a few if you'd like to save them for topping later. Cover the jar tightly and refrigerate for at least 2-3 hours, though overnight is ideal for the oats to fully soften and absorb all the flavors. I find that overnight oats taste better the longer they sit—the flavors meld together beautifully and the texture becomes perfectly creamy.
Remove the jar from the refrigerator and give it a quick stir to recombine any separation that may have occurred. If the oats seem too thick, add a splash of almond milk to reach your desired consistency. Transfer to a bowl if desired, or eat straight from the jar. Add any additional toppings you'd like such as extra berries, nuts, or a drizzle of honey before enjoying.