Heat oven to 325°F. Lightly grease bottom and sides of 9-inch springform pan. Sprinkle graham cracker crumbs over bottom and sides of pan.
In large bowl, beat cream cheese at medium speed until smooth and creamy. Gradually add sugar, beating until smooth. At low speed, add eggs 1 at a time, beating just until blended. Add liqueur and orange peel; beat 2 minutes at medium speed, scraping sides of bowl occasionally.
In small bowl, reserve 1 1/2 cups of batter. Pour remaining batter into crumb-lined pan. Slowly blend melted chocolate into reserved batter. Spoon chocolate batter by teaspoonfuls onto batter in pan, forming 9 drops around outside and 5 drops in center, using all the batter. Starting in center ofone outer drop, run knife through center of outer drops; run knife through inner drops, forming 2 circles of hearts.
Bake at 325°F. for 1 hour or until set.* Cool 1 hour. Refrigerate at least 3 hours or overnight. Store in refrigerator. Just before serving, remove sides of pan.