Chocolate Ganache Tart

Before you start

This tart is two components and nothing else: a fully baked cocoa shortcrust and a silky ganache that sets at room temperature. Because the filling never goes in the oven, the shell carries all the texture, so bake it until it is crisp right through. The ganache here uses about 1 part chocolate to 1.2 parts cream by weight with a little butter and honey, which slices cleanly but still feels soft on the tongue.

The chocolate you buy decides the result. A bar of 60 to 70% cacao gives a deep, balanced flavor and sets at the right firmness. Chocolate chips contain stabilizers that keep them from melting smoothly, and very high cacao bars above 75% set firmer and can turn grainy. Pour the ganache warm, around 35°C (95°F), so the top levels out on its own.

Ingredients

• Cocoa shortcrust160 g (1¼ cups plus 1 tbsp) all-purpose flour
• 30 g (⅓ cup) Dutch-process cocoa powder
• 80 g (⅔ cup) powdered sugar
• ¼ tsp fine salt
• 115 g (½ cup) unsalted butter — cold, cubed
• 1 large egg yolk
• 1 to 2 tbsp ice water
• Ganache250 g (about 1⅔ cups chopped) dark chocolate, 60 to 70% cacao — finely chopped
• 300 ml (1¼ cups) heavy cream
• 1 tbsp (21 g) honey or light corn syrup
• ⅛ tsp fine salt
• 30 g (2 tbsp) unsalted butter — very soft
• Finish½ tsp flaky sea salt — optional

Method

1. Pulse the flour, cocoa, powdered sugar and salt. Add the cold butter and pulse until no pieces larger than lentils remain. Add the yolk and 1 tablespoon of water and pulse until the dough holds when pinched, adding the second tablespoon only if needed.
2. Flatten the dough into a disc, wrap it and chill for 1 hour. Roll it between parchment to 3 mm (⅛ in) thick, fit it into the pan, trim the edge and prick the base. Chill the lined pan for 30 minutes.
3. Heat the oven to 175°C (350°F). Line the shell with parchment and weights and bake for 18 minutes. Remove the weights and bake 8 to 10 minutes more, until the base looks dry and matte and smells toasty. Cocoa dough hides browning, so trust the dry surface and the time. Cool completely.
4. Put the chopped chocolate and salt in a heatproof bowl. Bring the cream and honey just to a simmer, with small bubbles at the edge, and pour it over the chocolate. Leave it untouched for 2 minutes.
5. Stir from the center outward in small circles with a spatula until the mixture turns smooth and glossy. Stir in the soft butter until it disappears. Stir gently; a whisk adds bubbles.
6. Let the ganache cool to about 35°C (95°F), when it feels just warm on your lip. Pour it into the cooled shell and tilt the pan gently to level it. Pop any bubbles with a toothpick.
7. Leave the tart at cool room temperature for about 2 hours, until the surface is set and no longer tacky. Sprinkle with flaky salt, remove the ring and slice with a knife dipped in hot water and wiped dry.

Tips for success

• Chop the chocolate finely and evenly. Large chunks stay solid after the cream has cooled, and reheating them risks a greasy ganache.
• The refrigerator speeds setting but dulls the shine. If you chill it, let the tart sit out for 30 minutes before serving so the ganache softens.
• Spread a thin layer of salted caramel over the base before pouring the ganache for a richer slice.

Substitutions

Dark chocolate

Milk chocolate needs less cream to set: use 300 g milk chocolate with 200 ml cream. The tart will be sweeter and softer.

Dutch-process cocoa

Natural cocoa works in the crust; it bakes slightly redder and tastes a little sharper. Or use 190 g all-purpose flour for a plain shell.

Heavy cream

Full-fat coconut cream works for a dairy-free filling with a mild coconut taste. Use a plant-based butter in both components.

Variations

Espresso ganache

Dissolve 2 tsp instant espresso powder in the hot cream before pouring it over the chocolate.

Raspberry layer

Spread 100 g seedless raspberry jam over the cooled shell, chill it for 10 minutes, then pour the ganache over it.

Troubleshooting

The ganache looks oily or split

It got too hot or was stirred too fast. Warm 2 tablespoons of cream, add it, and stir slowly from the center until the emulsion comes back. An immersion blender held below the surface also rescues it.

Grainy or lumpy filling

The chocolate did not melt fully or contained chips. Set the bowl over barely simmering water for 20 seconds at a time, stirring, until smooth.

The filling never firmed up

Too much cream for the chocolate used, or the chocolate was below 55% cacao. Chill the tart for 1 hour; next time keep to the ratio above.

The crust is hard to cut

It was rolled too thick or overbaked. Aim for 3 mm and cut with a hot knife, pressing straight down through the crust.

Storage

Cover and keep the tart at cool room temperature, below about 21°C (70°F), for up to 1 day, or refrigerate for up to 4 days. Bring chilled slices back to room temperature for the best texture. The ganache can develop a dull bloom after several days in the fridge, but it is still fine to eat.

Safety notes

Do not taste the raw dough; it contains raw flour and egg yolk. Contains wheat, egg and milk. Dark chocolate contains some caffeine.