Arrange 20 ladyfingers around the edges and 12 ladyfingers on the bottom of an ungreased 8-in. springform pan; set aside. In a small saucepan, sprinkle gelatin over cold lime juice; let stand for 1 minute. Heat over low heat, stirring until gelatin is completely dissolved; cool.
Meanwhile, beat cream cheese and sugar until smooth. Gradually beat in melted chocolate, lime zest and gelatin mixture. Fold in whipped cream. Pour into prepared pan. Cover and refrigerate until set, about 3 hours. Remove sides of pan. If desired, garnish with strawberry and lime slices.