Rich Chocolate Tart

Make the crust dough: Beat egg yolk and cream together in a small bowl. In a food processor, pulse the toasted almonds and sugar until finely ground, 15–20 seconds. Add flour and salt; pulse to combine, about 10 pulses. Scatter cold butter over the flour mixture; pulse until the mixture resembles coarse breadcrumbs, about 15 pulses. With the processor running, add the egg yolk mixture and process until the dough forms a ball, about 10 seconds. Press into a 15 cm / 6-inch disk, wrap in cling film, and refrigerate until firm but malleable, about 30 minutes.

Roll out the dough between two large sheets of cling film into a 28 cm / 11-inch round, about 1 cm / 3/8 inch thick. Refrigerate on a baking sheet until firm but pliable, about 15 minutes.

Heat oven to 190°C / 375°F. Grease a 23 cm / 9-inch tart pan with removable bottom. Remove the top layer of cling film and invert the tart pan onto the dough. Flip both together, remove the sheet and peel off the cling film. Roll a pin over the edges to cut the dough. Press the dough evenly into the base and fluted sides (about 6 mm / 1/4 inch thick). Trim any excess above the rim. Freeze until firm, 20–30 minutes.

Blind-bake: Line the tart with foil (greased side down) and fill with pie weights or dried beans. Bake for about 25 minutes until the pastry is dry and lightly golden, rotating the pan halfway. Remove the foil and weights; bake a further 8–10 minutes until deep golden and fragrant. Cool completely on a wire rack.

Make the filling: Reduce oven to 120°C / 250°F. Bring the cream, espresso powder, and salt to a simmer in a small saucepan over medium heat. Place the chopped chocolate in a large heatproof bowl, pour the hot cream over it, cover, and let stand 5 minutes. Whisk slowly and gently (avoid incorporating air) until smooth. Add the softened butter and whisk until fully incorporated. Strain the eggs through a fine-mesh sieve into the chocolate mixture; whisk gently until the mixture is smooth and glossy.

Pour the filling into the cooled tart crust. Gently shake side to side to level the surface. Pop any large bubbles with a toothpick. Bake on a baking sheet at 120°C / 250°F for 30–35 minutes until the outer edge is just set and faint cracks appear on the surface — the centre will still be very wobbly. Cool completely on a wire rack, then refrigerate uncovered until the filling is fully set, at least 3 hours or up to 18 hours.

Glaze the tart: Remove from the fridge 30 minutes before glazing. Bring the cream and corn syrup to a simmer in a small saucepan, remove from heat, add the chopped chocolate, and cover. Let stand 5 minutes, then whisk gently until smooth. Whisk in the hot water until the glaze is shiny and pourable.

Pour the glaze onto the centre of the tart and tilt the pan to let it flow to the edges — do not spread with a spatula or it will leave marks. Pop any bubbles with a toothpick. Let stand at room temperature for at least 1 hour before serving.

To serve, remove the outer ring. Slide a thin spatula between the crust and the pan base to loosen, then transfer to a serving plate. Cut into wedges and serve with lightly sweetened whipped cream (flavour with cognac or vanilla if you like). The tart can be garnished with chocolate curls or a pinch of flaky sea salt.