Pumpkin-Chocolate Tart

1. Preheat oven to 350. In a medium bowl, whisk together pumpkin puree, brown sugar, creme fraiche, eggs, cinnamon, ginger, nutmeg, salt and cloves until smooth. Pass mixture through a fine sieve set over a clean bowl; discard solids. Pour filling into prepared curst.
2. Bake until filling is set, about 40 minutes. Transfer to wire rack, and let cool at least 30 minutes.
3. Set a heatproof bowl, or the top of a double boiler, over a pan of barely simmering water. Melt chocolate in bowl, stirring occasionally; remove from heat. Dip a spoon in melted chocolate, then drizzle chocolate over tart, forming decorative stripes. Refrigerate until well set, at least 1 hour and up to 1 day.
Crust
1. In a bowl of an electric mixer fitted with the paddle attachment, combine flour, sugar, cocoa, salt, cinnamon and cloves. Add butter; mix on low speed until butter is the size of small peas, about 5 minutes. Add egg; mix until ingredients come together to form a dough.
2. Preheat oven to 350. On a lightly floured work surface, roll out dough to just thicker than 1/8 inch. Brush off excess flour; transfer dough to a 10 inch tart pan with a removable bottom. Press dough into bottom and up sides of pan; trim excess flush with edge. Lightly prick bottom of dough all over with a fork. Chill until firm, about 30 minutes.
3. Bake shell until firm, about 15 minutes. Immediately sprinkle chocolate over bottom of shell; smooth with a spatula.