Pour the graham cracker crumbs in a shallow dish. Rub a lime wedge around the edge of a martini glass and roll the edge in the graham cracker crumbs. Chill the glass for 30 minutes or until ready to serve.
Combine the vanilla vodka, key lime liqueur, pineapple juice, and cream in a shaker. Fill the shaker half full with ice and shake until well blended. Pour into prepared martini glass, garnish with a lime wedge and serve immediately.