Heat oven to 375°F. Line 15x10x1-inch pan with foil; place wire rack in pan. In large bowl, mix beef, Sriracha and Worcestershire sauces, onion powder and salt. Shape mixture into 18 (1 1/2-inch) balls. Press thumb in center of each to form an indent. Press 1 cheese cube into center of each ball, sealing it inside. Flatten each ball slightly and place on rack. Bake 20 to 23 minutes or to internal temperature of 160°F. Cool 2 to 3 minutes.