250g dark chocolate, broken into 3–4cm pieces
4 large eggs
280g caster sugar
120g plain flour
30g cocoa powder
200g halva, broken into 2cm pieces
80g tahini paste
Preheat the oven to 200 degrees Celcius. Grease and line a 23cm square or 30 x 20cm rectangular baking tin with baking parchment and set aside.
Melt the butter and chocolate together. Stir through, until you have a thick shiny sauce, and 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, longer by hand. Add the chocolate and fold through gently using a spatula – don’t overwork the mix here.
Sift the flour and cocoa 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 tin, using a small spatula to even it out. Dollop small spoonfuls of the tahini paste 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 tin.
Bake for about 23 minutes, until the middle has a slight wobble and it is gooey inside – they may be ready anywhere between 22 and 25 minutes. If using the 30 x 20cm tin, they will need a couple of minutes less. They may seem a little under-cooked at first, but they firm up once they start to cool down. If you want to serve them warm-ish (and gooey), set aside for just 30 minutes before cutting into 16 pieces. Otherwise, set aside for longer to cool to room temperature.