1 cup graham cracker crumbs
1/4 cup sugar
1 cup lime juice
1/4 cup water
2 (1/4-ounce) envelopes unflavored gelatin
1 1/2 cups sugar
1 tablespoon freshly grated lime zest
2 (8-ounce) packages cream cheese, softened
1/2 cup whipping cream
Lime slices, if desired
Stir together all crust ingredients in medium bowl. Press onto bottom of ungreased 9-inch springform pan. Set aside.
Combine lime juice and water in 2-quart saucepan; sprinkle with gelatin. Let stand 5 minutes to soften. Add sugar, eggs and lime zest. Cook over medium heat, stirring constantly, until mixture just comes to a boil (7 to 8 minutes). (DO NOT BOIL.) Set aside.
Combine butter and cream cheese in large bowl. Beat at medium speed, gradually adding hot lime mixture and scraping bowl often, until well mixed. Refrigerate, stirring occasionally, until cool (about 45 minutes).
Beat whipping cream in chilled small bowl at high speed, scraping bowl often, until stiff peaks form. Gently stir into lime mixture. Pour into prepared crust. Cover; refrigerate until firm (3 to 4 hours).
Loosen sides of cheesecake from pan by running knife around inside of pan. Garnish top of cheesecake with whipped cream and lime slices, if desired. Store refrigerated.