Lightly coat a 2-quart rectangular baking dish with cooking spray; set aside. In a medium saucepan cook onion and sweet pepper in 4 teaspoons of the butter about 5 minutes or until tender. Stir in flour until vegetables are coated. Add milk all at once. Cook and stir until thickened and bubbly; remove from heat and set aside.
In a large bowl stir together the eggs, thawed corn, 1 cup of the bread crumbs, the salt, and pepper. Stir in the thickened mixture. Transfer mixture to the prepared baking dish. In a small saucepan melt the remaining butter. Stir in the remaining bread crumbs to coat. Sprinkle over corn mixture.
Bake, uncovered, in a 325 degree F oven for 40 to 45 minutes or until center appears just set. Let stand 10 minutes before serving. Makes 12 servings.