This recipe is derived from the second, “corrected” edition of “Sweet” by Yotam Ottolenghi and Helen Goh. We improved it – mainly by changing the oven temp and baking time – and tweaked the ingredients a little. They are dark, rich, gooey – and, in a word, sensational.
1 cup plus 6 tablespoons unsalted butter, cut into ¾-inch cubes, plus extra for greasing
11 ounces (312g) semi-sweet chocolate, broken into 1½-inch pieces
5 large eggs, at room temperature
1¾ cups granulated sugar
1¼ cups all-purpose flour
⅓ cup plus 2 tablespoons Dutch-processed cocoa powder
¾ teaspoon salt
8 ounces (225g) halva, broken into ¾-inch pieces
½ cup tahini
Preheat the oven to 350°F/175°C degrees. Grease a 9-by-13-inch pan, line with enough parchment paper to create a ¾-inch overhang and then set aside.
Place the butter and chocolate in a heatproof bowl over a pan of simmering water, making sure that the base of the bowl is not touching the water. Leave for 7 to 8 minutes to melt, then remove the bowl from the heat. Stir until you have a thick shiny sauce and then set aside to come to room temperature.
Place the eggs and sugar in a large bowl and whisk until pale and creamy and a trail is left behind when you move the whisk; this will take about 3 minutes with an electric mixer on medium speed, longer by hand. Add the chocolate and fold through gently with a spatula—don’t overwork the mixture here.
Sift the flour, cocoa powder and salt into a bowl; then gently fold into the chocolate mixture. Finally, add the pieces of halva, gently fold through the mix, then pour or scrape the mixture into the lined baking pan, using a small spatula to even it out. Dollop small spoonfuls of tahini into the mix in about 12 different places; then use a skewer to swirl them through to create a marbled effect, taking the marbling right to the edges of the pan.
Bake for 40 minutes, or until the middle has a slight wobble and a wooden skewer comes out with a few crumbs clinging. They may seem a little undercooked at first, but they firm up once they start to cool down. If you want to serve them warmish (and gooey), set aside for just 30 minutes before cutting into 20 pieces. Otherwise, set aside for longer to cool to room temperature.
Storage: These will keep well for up to 5 days in an airtight container. They also freeze well, covered in plastic wrap, for up to a month. When you take them out of the freezer, they are uncommonly good eaten at the half-frozen, half-thawed stage.