Although most tarts are open-faced creations, this one has a top and bottom crust. They encase a dense, buttery filling of homemade caramel and walnuts and the whole thing is then glazed with chocolate and decorated with more walnuts. In a word: WOW. A single slice of it might be viewed as the world’s most elegant candy bar.
1. To make filling: Combine sugar, honey or corn syrup and 2 1/2 tablespoons in a medium-large, heavy saucepan. Cook over low heat for a few minutes, stirring occasionally, until sugar has dissolved. Use a moistened pastry brush to wash down any sugar crystals that have formed on the sides of the saucepan.
2. Cover saucepan, raise heat to medium and cook, without stirring, until the mixture has turned an amber color, 10-15 minutes. Move the pan occasionally to swirl the mixture as it cooks, but again, don’t stir it.
3. Stir in 4 1/2 tablespoons room-temperature butter into the mixture until dissolved. Stir in cream and chopped walnuts. Boil this mixture gently until it reaches 225 degrees on a thermometer. Let it cool off the heat for about 10 minutes, then stir in the honey and liqueur. Let it cool to room temperature.
4. To assemble and bake the tart: Heat oven to 350 degrees. Butter and flour an 8-inch cake pan, one that is at least 1 1/2 inches deep. Working on a floured surface, divide the chilled tart dough into 2 portions, one that is about 9 ounces in weight, and one that is about 6 ounces. Knead the pieces briefly between your hands to soften and smooth the dough. Roll out the larger portion into a round that will fit into the bottom and up the sides of the pan. Press this round gently into the pan and brush all the surfaces with egg white.
5. Pour the cooling filling into the pan. Roll out the smaller dough portion into a round to fit over the top of the filling. Brush the top edge of the bottom crust with more egg white. Lay the second round of dough over the top of the tart and press the top and bottom crust edges together to form a seal all around.
6. Bake tart until surface is lightly browned, about 30 minutes. Cool it completely. Run a thin-bladed knife around the sides of the completely cooled tart to loosen it. Slide the tart out onto a platter. Cover it with a dome or aluminum foil and chill it thoroughly.
7. To finish the tart: Make a glaze by melting the chocolate and 4 tablespoons butter in a double boiler over simmering water. (Alternatively, you can use a microwave oven for this, but take care not to scorch the chocolate.) Cool glaze to room temperature or slightly warm.
8. Spread the glaze evenly around the sides and top of the tart. (If glaze is too firm to spread, warm it briefly in a microwave oven.) Place walnut halves around the outer rim on the top of the tart. Chill for 10-20 minutes to set the glaze. Serve the tart chilled or at room temperature.
From The Ovens of Brittany Cookbook, by Terese Allen. Recipe originally by Amy Nadeau and Jeanette Dykema.