Coat a 1 1/2-quart soufflé dish with cooking spray; sprinkle with breadcrumbs. Set aside.
Coat a large nonstick skillet with cooking spray; place over medium-high heat until hot. Add corn and green onions; sauté 5 minutes or until tender. Remove from heat, and stir in ham; set aside.
Place the flour in a small saucepan. Gradually add milk, stirring with a wire whisk until blended. Cook over medium heat 3 minutes or until thickened, stirring constantly. Remove from heat; stir in cheese and pepper.
Beat egg yolks in a medium bowl at high speed of a mixer until thick and pale (about 5 minutes). Gradually add hot milk mixture to egg yolks, stirring constantly. Stir in the corn mixture, and set aside.
Beat egg whites (at room temperature) and cream of tartar in a large bowl at high speed of a mixer until stiff peaks form. Gently stir one-fourth of egg white mixture into corn mixture. Gently fold in remaining egg white mixture.
Pour mixture into prepared soufflé dish. Bake at 325° for 1 hour or until puffed and golden. Serve immediately.