Add milk, cottage cheese, maple syrup, cinnamon, and salt to a blender. Blend until smooth, about 10-15 seconds.
Pour the milk mixture into a small jar or food storage container. Add oats and ground flaxseed, and mix well until combined.
Cover with a lid and refrigerate overnight, or for at least three hours.
When you’re ready to eat, transfer oats to a bowl. Add toppings right before serving.*
Notes
*If you want to enjoy these cinnamon overnight oats warm, transfer to a microwave-safe bowl before serving. Heat in the microwave for 45-60 seconds, stirring every 15 seconds. Add toppings immediately before eating.