about 30 to 36 appetizers
Lightly butter one side of each bread slice, if desired. Arrange bread slices, buttered-side up on an un-greased baking sheet or sheets; broil, about 6 to 8 inches from heat source, for 2 to 3 minutes or until bread slices are toasted. Remove from oven and turn slices un-toasted-side up on baking sheet(s); set aside.
In a medium bowl, combine egg, cream cheese, mayonnaise, Worcestershire sauce, mustard, garlic juice, salt, and hot pepper sauce, beating with an electric mixer until mixture is light and fluffy. Stir in Parmesan cheese and green onion, mixing well.
Spoon a small amount of cheese mixture on the un-toasted side of each bread slice, spreading evenly and covering the top of the bread slice. Bake in a preheated moderate oven (350 degrees F.) for about 10 minutes or until appetizers are thoroughly heated and filling is puffed. Sprinkle the top of each lightly with paprika. Arrange appetizers on a serving tray, garnish as desired, and serve immediately.