Marbled Cheesecake Hearts

2 cups finely crushed crème-filled chocolate sandwich
    cookies (about 24 cookies)
3 tablespoons butter or margarine, melted
24 ounces cream cheese, softened
1 (14 ounce) can sweetened condensed milk
3 eggs
2 teaspoons vanilla extract
4 (1/2 ounce) sections unsweetened chocolate, melted

Preheat oven to 300 degrees F. Line a 9 x 13-inch baking pan with heavy foil; set aside.

Combine crumbs and butter; press firmly on bottom of foil-lined pan.

With mixer, beat cream cheese in large bowl until fluffy. Gradually beat in sweetened condensed milk until smooth. Add eggs and vanilla extract; mix well.

Pour half of the batter evenly over prepared crust. Stir melted chocolate into remaining batter; spoon over vanilla batter. With a table knife or metal spatula, gently swirl chocolate batter through vanilla batter to marble.