Coconut-lime Bars with Hazelnut Shortbread Crust

For crust: Position rack in center of oven and preheat to 350F. Blend nuts and sugar in processor until nuts are finely ground. Add flour and salt; blend 5 seconds. Add butter and process until well blended. Press dough evenly onto bottom of 13 x 9 x 2-inch metal baking pan. Bake crust until golden brown, about 28 minutes; cool completely in pan on rack. Maintain oven temperature. For filling: Whisk sugar and eggs in large bowl until well blended, scraping down sides of bowl occasionally. Whisk in lime juice, then flour and lime peel. Pour filling over crust in pan. Bake lime bars 25 minutes (filling will not be fully set). Sprinkle coconut evenly over. Bake until filling is completely set, about 10 minutes longer. Cool bars in pan on rack. Chill uncovered until cold, at least 2 hours. DO AHEAD: Can be made 1 day ahead. Cover and keep chilled. Cut around pan sides to loosen bars; cut into 24 pieces. Using small spatula, transfer bars to platter; serve chilled.