Preheat oven to 375°F. On a lightly floured surface, roll out dough 1/8 inch thick, 1 disk at a time. Cut out twenty-four 4-inch rounds, and fit dough into two dozen 3-inch tart pans. Trim dough flush with rims. Pierce bottoms of shells all over with a fork. Refrigerate or freeze until firm, about 30 minutes.
Line tart shells with parchment, and fill with pie weights or dried beans. Bake until edges are golden, about 15 minutes. Remove parchment and weights; continue baking until crusts are golden brown all over, about 10 minutes. Let cool completely on a wire rack.
Fill tart shells halfway with pastry cream and top with berries, arranging in concentric circles. If desired, in a small saucepan over low heat, heat apricot jam until loose, then pass through a fine sieve. Gently brush berries with strained jam. Serve immediately or refrigerate up to 2 hours.
