Key limes are smaller than Persian limes; they have a greenish-yellow rind and a stronger, more sour-acidic flavor. They have a short growing season, usually June through August. If they're not in season, you can substitute bottled Key lime juice and Persian lime zest.
To prepare crust, place first 5 ingredients in a food processor; process until finely ground. Add oil; pulse 2 to 3 times or until combined.
Wrap 2 layers of foil around bottom and outside of a 9-inch springform pan; coat inside of pan with cooking spray. Firmly press crust mixture into bottom and 1/2 inch up sides of pan. Bake at 325° for 5 minutes. Cool completely on a wire rack.
To prepare cheesecake, place cheeses in a large bowl; beat with a mixer at medium speed until smooth. Add sugar and next 5 ingredients (through salt); beat well. Add eggs, 1 at a time, beating well after each addition. Add Key lime juice, beating at low speed until blended.
Pour cheesecake batter over cooled crust. Place springform pan in a shallow roasting pan; add enough hot water to come halfway up sides of springform pan. Bake at 325° for 1 hour and 5 minutes or until center barely moves when pan is touched. Turn oven off; cool cheesecake in closed oven 30 minutes. Remove cheesecake from oven; run a knife around outside edge. Cool to room temperature. Cover and chill at least 8 hours. Garnish with lime.
Gluten-Free Baking; The Food Lover's Gluten-Free Cookbook