Miniature vanilla cheesecakes with swirls of semisweet chocolate and cocoa pastry crusts.

Marbled Cheesecake Tarts

3/4 cup all-purpose flour
1/3 cup granulated sugar
1/4 cup unsweetened baking cocoa
1/8 teaspoon salt
1/3 cup butter
3 tablespoons water
1 (3-ounce) package cream cheese
3 tablespoons granulated sugar
1/2 cup sour cream
1 large egg yolk
1/2 teaspoon vanilla extract
1/2 cup semisweet chocolate chips

1. In a mixing bowl sift together flour, 1/3 cup sugar, unsweetened baking cocoa, and salt. Cut in butter until the mixture resembles coarse crumbs. Sprinkle with up to 3 tablespoons water, 1 tablespoon at a time, tossing gently until moistened, and the mixture forms a ball. Divide into 1-inch balls and press into ungreased muffin tins.
2. In another bowl, beat together cream cheese with 3 tablespoons sugar until fluffy. Beat in sour cream, egg yolk, and vanilla, until smooth and creamy. Spoon mixture evenly among the muffin cups. Evenly divide and sprinkle semisweet chocolate chips on top of the cream cheese mixture.
3. Bake in a 325°F (160°C) oven for about 5 minutes. With a knife slightly swirl the melted chocolate into the filling. Return to the oven and bake for an additional 20 to 25 minutes, or until the filling is set. Cool for 10 minutes before removing from the pan.

Makes 6 tarts.