Recipe: baked oatmeal casserole with berries

I found this recipe thanks to someone sharing it on facebook the other day. I made it a couple mornings ago for David and my parents, and you guys it was so good! It was easy, and delicious. You can find the original recipe HERE. 

2 cups of oats
1/3 cup brown sugar
1 teaspoon of baking powder
1 teaspoon cinnamon
1/2 teaspoon salt
1/2 cup chocolate chips
1 cup strawberries
2/3 cup blueberries
1 banana
2 cups milk
1 large egg
2 tablespoons butter
1 teaspoon vanilla

1: Set oven to 375.
2: Spray a 10x10 casserole dish. (I only had a 9x13, and it worked perfectly fine!)
3: In a large bowl, mix oats, brown sugar, baking powder, cinnamon, salt, half of the chocolate chips, and half of the berries. Stir well and then pour into the casserole dish.
4: Add the other half of the berries and chocolate chips to the top of the mixture. Then slice the banana and add it to the top.
5: In a separate bowl, stir the milk, egg, butter, and vanilla. Whisk thoroughly, and then pour on top of the oatmeal mixture, making sure it is covered evenly.
6: Bake for 30 minutes, then remove the casserole dish and add a tablespoon of brown sugar to the top of the casserole for added sweetness (optional). Bake for an additional 5-10 minutes or until the top is golden brown.