Heat oven to 350°F. In 10-inch skillet, cook ground beef over medium-high heat 5 to 7 minutes, stirring occasionally, until thoroughly cooked; drain. Stir in pepperoni and pizza sauce. Cook 2 to 3 minutes over medium heat until hot. Stir in Italian cheese blend and 1 cup of the Cheddar-American cheese blend until melted.
Arrange bread slices on 2 ungreased cookie sheets. Spread generous tablespoon of beef mixture on each slice. Top each with about 1 teaspoon of the remaining cheese.*
Bake 15 to 20 minutes or until thoroughly heated and crisp. Serve warm.