Preheat oven to 350 and grease a 9x13 baking pan with cooking spray.
In a small bowl, cream butter and sugar. Beat in eggs, milk and vanilla. Stir in squash. Pour into prepared pan.
Bake for 45 minutes and remove from oven when almost set.
Combine topping ingredients and sprinkle over squash. Bake for an additional 5-10 minutes or until bubbly and browned.