Chilling time:
45 mins

Special equipment:
9in (23cm) springform pan
food processor with blade attachment

Ingredients:
1¼ cups all-purpose flour, plus extra for dusting
5 tbsp unsalted butter, plus extra for greasing
¼ cup sugar
¼ tsp salt
1 large egg

For the filling:
1½ cups walnuts
½ cup sugar
2oz (60g) good-quality dark chocolate, chopped
11 tbsp unsalted butter
2 tsp all-purpose flour
2 large egg yolks, plus 1 large whole egg
1 tsp pure vanilla extract

For the chocolate glaze:
16oz (175g) good-quality dark chocolate, chopped
5 tbsp unsalted butter
2 tsp Grand Marnier
cocoa powder, for dusting

Method:
1 Sift the flour on to a work surface and make a well in the center.

2 Pound the butter with a rolling pin to soften. Put the butter, sugar, salt, and egg into the well. With your fingertips, work the ingredients in until well mixed.

3 Work the flour until coarse crumbs form. Press the dough into a ball. Knead for 1–2 minutes, until smooth. Wrap in plastic wrap and chill for 30 minutes.

4 Grease the pan. Roll the dough into an 11in (28cm) round. Wrap it around the rolling pin and gently press into the pan, sealing any cracks.

5 Prick the bottom of the shell with a fork. Chill for 15 minutes, until firm.

6 Preheat the oven to 350°F (180°C). Spread out the nuts on a baking sheet and toast in the heated oven until they are lightly browned, 5–10 minutes. Stir occasionally, so they color evenly. Let cool.

7 Return the baking sheet to the oven. Reserve 8 walnut halves. Grind the remaining nuts with the sugar in a food processor, then empty into a bowl. Chop the chocolate in a food processor.

8 Beat the butter until creamy. Add the flour and the hazelnut mixture and continue beating for 2–3 minutes, until light and fluffy. Add the yolks and egg, one at a time, beating after each addition.

9 Mix in the chocolate and vanilla extract. Spread the filling over the pastry shell and smooth the top.

10 Bake 35–40 minutes, until a metal skewer inserted in the center comes out clean. Let cool on a wire rack. While the tart cools, put the chocolate for the glaze in a bowl set over a saucepan of simmering water, stirring occasionally, just until melted. Dip the reserved walnuts in the chocolate to coat, then set aside.

11 Cut the butter into small pieces and gently stir it into the warm melted chocolate in 2–3 batches. Add the Grand Marnier. Let cool to tepid. Set the tart pan on a bowl to loosen and remove the side.

12 Spread the glaze over the tart. Let cool. Just before serving, sift cocoa powder over and arrange the walnuts on top. Serve at room temperature.

STORE:
The tart can be baked and stored for up to 2 days in an airtight container, but the flavors will mellow. Add the glaze
not more than 4 hours before serving.

PREPARE AHEAD:
This can be made up to 2 days ahead and kept, tightly wrapped, in the refrigerator

BAKER’S TIP:
Toasting nuts intensifies their flavor and adds crunch to their texture. You can tell that they are toasted when the skins start to pop and the nuts smell fragrant. Although the walnut skins are not removed in this recipe, toasting also makes it easier to remove thin skins from nuts.

Chocolate Walnut Truffle Tart