Preheat oven to 400 degrees. Grease casserole dish with non-stick baking spray.
Layer half of the marshmallows, half graham crackers and half chocolate bar pieces. Repeat layers.
Bake for 10 minutes or until marshmallows are golden.
While the s'mores bake, melt chocolate in a microwave safe bowl. When s'mores dip comes out of the oven, drizzle melted chocolate over the top. Enjoy!