Zest 2 clementine to make 2 tsp. finely grated zest; set aside. Peel the clementine and cut each in half, crosswise; set aside.
Combine sugar and water in a saucepan set over medium heat; bring to boil. Reduce heat and simmer. Add clementine halves. Simmer for 20 minutes or just until tender. Cool in syrup; set aside.
Stir graham crumbs with butter. Divide crumb mixture evenly among four 1/2 cup mason jars; pack well. Refrigerate for 10 minutes or until firm.
Beat cream cheese, condensed milk, vanilla and reserved clementine zest with electric beaters until light and fluffy. Divide evenly among the jars. Chill to set.
Before serving, top each cheesecake with two poached clementine halves.
Tip: Cheesecakes and poached clementine can be made 1 to 2 days in advance. Store separately covered in refrigerator until ready to serve.
