Step 1

Mix the ingredients: Add all ingredients (except for the blueberries if using frozeto a large bowl. Mix well.

Step 2

Add to a casserole dish: Lightly grease a 7x11 inch rectangular baking dish and spread the oat mixture in it. (If using frozen berries, add half the oat mixture to the dish and sprinkle with half the berries, then repeat layers.)

Step 3

Chill the dish: Cover the casserole dish (you can use either plastic wrap or even a towel). Chill in the fridge overnight.

Step 4

Bake the dish: The next morning, remove the dish from the fridge. Preheat the oven to 350°Bake until set and golden on top, about 30-35 minutes. Rest the casserole dish on a cooling rack for 5-10 minutes, then slice to serve.