Season shrimp. heat large skillet over medium-high; add 1/2 tbsp. butter and shrimp. Cook shrimp through, 1 to 2 minutes; transfer to plate. Over medium-low heat melt 1 tbsp. butter; add shallots, lime juice and crushed pepper; cook 2 minutes. Add remaining butter, zest, shrimp and cilantro; toss.
