Make crust: Preheat oven to 350 degrees. Combine flour, confectioner's sugar, cocoa and salt in food processor bowl and process until blended. Add cold butter and process until blended. Add egg yolk and process. Chill while preparing pan: Lightly butter 8-inch tart pan with removable bottom or tart ring and baking sheet. Turn out crust mixture and press evenly onto sides and bottom of pan. Place aluminum foil on top and add pie weights or dried beans. Bake 30 minutes. Remove foil and weights and cool on rack.

Make passion fruit curd: Combine egg yolks and sugar in heavy saucepan. Whisk together until well blended. Stir in passion fruit, softened butter and salt. Cook and stir with a wooden spoon over low heat until the mixture has thickened and coats the back of the spoon. If you use a thermometer, it should read 196 degrees. If the mixture starts to bubble, immediately take off heat and whisk – do not let it boil. Strain cooked curd into a bowl and cool completely.

Make chocolate ganache: In food processor, add chocolate and process until chocolate becomes a fine powder. Heat cream just until tiny bubbles appear on the side. With processor running, add cream slowly until it's all incorporated. Use a spatula to scrape sides, blend briefly again, and cool. Stir in liqueur. Chill in refrigerator for 30 minutes until thickened.

To assemble: Spread passion fruit curd in cooled crust. Carefully spread cooled ganache on top – keep it just short of reaching the edges of the crust so the orange curd – the "sun" – remains visible. Chill until ready to serve.

Passion fruit curd and chocolate ganache recipes adapted from The Cake Bible by Rose Levy Beranbaum.