Caramelize onions by sauteing in oil until they are brown and slightly sticky, about 20 to 25 minutes. Remove from heat and set aside.
Cut bread into 2-inch rounds, using a biscuit cutter or a glass. Toast 1 side. Season cream cheese with Worcestershire sauce, seasoned salt, black and red pepper and paprika. Spread cream cheese mixture on toasted side of the bread rounds. Top center with caramelized onions. Frost with mayonnaise and sprinkle lightly with paprika. Bake until toasted and bubbly, about 15 to 20 minutes.