MINI BLACK AND WHITE CHOCOLATE TARTLETS

Steps:

• On a lightly floured surface, roll out dough 1/8 inch thick. Line twenty-four 3 3/4-by-1 3/4-inch rectangular tart pans, rerolling scraps as needed. Pierce bottoms of shells all over with a fork. Transfer pans to a parchment-lined rimmed baking sheet; refrigerate or freeze until firm, about 30 minutes.
• Meanwhile, preheat oven to 350°F. Bake shells until dry, 15 to 18 minutes. Let cool completely on a wire rack.
• In a small bowl, sprinkle gelatin over the ice water. Let soften about 5 minutes. Meanwhile, in a small saucepan, bring 1/2 cup cream to a boil. Remove from heat. Add softened gelatin, stirring for 30 seconds to dissolve completely.
• Put the white chocolate in the bowl of a food processor. With machine running, pour in softened gelatin mixture; process until smooth. Transfer to a medium bowl. Cover, and refrigerate until mixture is almost the consistency of pudding, about 15 minutes; stir until smooth.
• In a medium chilled bowl, whisk remaining 3/4 cup cream just until stiff peaks form. Fold into white chocolate mixture until combined.
• Put mousse in a pastry bag fitted with a 5/16-inch star tip (#22). Pipe into cooled tart shells.
• Preheat oven to 350°F. On a lightly floured surface, roll out dough 1/8 inch thick. Fit dough into twenty-four 3-inch fluted tart pans, or the cups of a standard muffin tin. Place pans on a rimmed baking sheet; refrigerate or freeze until firm, about 30 minutes. Bake until dry, 18 to 20 minutes. Let cool completely; unmold shells from pans.
• Place chopped bittersweet chocolate in a heatproof bowl. In a small saucepan over medium heat, bring cream and espresso powder to a simmer. Pour over chopped chocolate, and let stand 5 minutes. Stir until smooth. Fill baked and cooled tart shells with chocolate mixture.
• Meanwhile, in a heatproof bowl set over (not in) a pan of simmering water, melt white chocolate, stirring. Transfer to a resealable plastic bag; snip a small opening in the corner. Working quickly, pipe 6 dots of melted white chocolate on filling in each tartlet. Using a wooden skewer or toothpick, swirl dots to marbleize. Gently tap tartlets on work surface to settle filling. Refrigerate until set, 1 hour or up to 1 day.