Preheat oven to 350°.
Combine first 4 ingredients in a large saucepan; stir in milk and hot sauce. Cook over medium heat until thick (about 15 minutes), stirring constantly. Place egg yolks in a medium bowl. Spoon 1/2 cup hot cornmeal mixture into egg yolks. Stir egg yolk mixture into remaining cornmeal mixture. Add butter, stirring until butter melts.
Place baking powder and egg whites in a medium bowl; beat with a mixer at high speed until stiff peaks form. Fold one-fourth of egg white mixture into cornmeal mixture. Fold remaining egg white mixture into cornmeal mixture. Gently spoon mixture into an 11 x 7-inch baking dish coated with cooking spray. Bake at 350° for 40 minutes or until lightly browned and puffy. Serve immediately.