On a lightly floured surface, roll Chocolate Pastry Dough to ⅛-inch thickness. Carefully transfer to a 9-inch fluted round removable-bottom tart pan, pressing dough into bottom and up sides. Using a small knife, trim excess dough. Prick bottom of dough all over with a fork. Refrigerate until firm, about 30 minutes.

Preheat oven to 325°F (160°C).

Top dough with a piece of parchment paper, letting ends extend over edges of pan. Add pie weights.

Bake until edges are set, about 15 minutes. Carefully remove parchment and weights. Bake until center is set and surface is dry, 5 to 7 minutes more. Let cool completely in pan on a wire rack.

In a medium microwave-safe bowl, place chopped chocolate and butter.

In a small microwave-safe bowl, heat cream on high in 15-second intervals just until it begins to steam (30 to 45 seconds total). Pour onto chocolate mixture; cover and let stand for 5 minutes. Whisk until melted and smooth. (If chocolate lumps remain, microwave for 10 seconds, and whisk again.) Spread chocolate mixture into cooled crust. Refrigerate until set, about 1 hour.

Spread Cherry Crème Légère evenly onto cold ganache; arrange cherries on top. Refrigerate for at least 1 hour before serving. Garnish with chocolate curls just before serving, if desired. Refrigerate in an airtight container for up to 3 days.