Tahini and Halva Blondies with Sesame Brittle

Blondies are the unsung sibling of the brownie, and for a long time I treated them as an afterthought, a beige consolation prize for people who do not like chocolate. Then I started building them around tahini, and they became something I make on purpose. This version is fudgy and dense in the middle, with the deep butterscotch hum of brown sugar and the savoury, faintly bitter edge of sesame paste running all the way through. Pockets of halva melt into soft, marbled veins, and a scatter of homemade sesame brittle on top gives every square a glassy, caramelised crunch. It is sweet, yes, but grown-up sweet, the kind of thing you can eat with strong coffee and not feel you have ruined your afternoon.

Where the blondie and halva meet

The blondie is the brownie’s paler relation, an American tray bake that swaps chocolate for brown sugar and butter and leans on vanilla and caramel notes for its flavour. Done badly it is a sweet, one-note beige square, which is why I ignored them for years. What rescues this version is a marriage with something much older: halva, the sesame-and-sugar confection eaten from the Balkans through Turkey, the Levant and India, whose name comes from the Arabic ḥalwā, meaning sweet. Sesame halva is made by whipping tahini into a boiled sugar syrup until it sets into a dense, crumbly, faintly flaky block. Folding it into a blondie built on tahini is really just reuniting the same two ingredients in a different form.

Tahini is toasted sesame seeds ground to a paste, and it behaves a little like a nut butter and a little like an oil, both of which are useful here. The fat keeps the crumb tender and gives that prized fudgy density, while the toasted-seed flavour brings a savoury counterweight to all the sugar. Sesame and brown sugar are old friends; the molasses notes in soft light brown sugar lean naturally towards the roasted, slightly tannic flavour of tahini. The result is more interesting than a plain blondie because it is not relentlessly sweet. There is a bitterness underneath, the same trick that makes salted caramel so moreish, and the same balance that a good tahini sauce relies on in savoury cooking.

Stir your tahini well before you measure it. The good stuff separates in the jar, with a slick of oil sitting on top of a stiff paste at the bottom, and you want it homogenous and pourable. A tahini that has gone claggy and dry at the base will make the batter stiff and the flavour harsh, so if yours is past its best, buy a fresh jar. It is the backbone of the whole tray.

Halva, the marbled middle

Halva is the other half of the equation, and it earns its place. Made by binding tahini with a boiled sugar syrup, it has a crumbly, fudge-like texture that melts beautifully when baked. As the blondies cook, the chunks soften and bleed slightly into the surrounding batter, leaving sweet, almost flaky seams that are denser and more intense than the crumb around them. I use plain vanilla halva, but the pistachio or chocolate-marbled kinds work too if that is what your corner shop sells. Break it into rough, generous pieces rather than crumbs; you want to find it when you bite in.

Fold most of it through the batter and save a handful to press into the top, where it will catch a little colour and look the part. Do not overmix once the halva goes in, or you will smear it into the batter and lose those distinct veins.

The sesame brittle, and the one clever twist

The twist that lifts these from very good to memorable is the sesame brittle scattered over the top. It is the easiest brittle in the world: toast sesame seeds, pour molten caramel over them, let it set, and smash it. What you get is a sheet of amber glass studded with seeds, sweet and bitter and snappy all at once. Half goes into the bake so it half-melts into the surface, and the rest goes on after cooling so it stays crisp and audible.

Caramel intimidates people unnecessarily. Use a clean, dry, light-coloured pan so you can read the colour, melt the 75g of sugar over a medium heat without stirring, and only swirl the pan gently if it is colouring unevenly. Stirring encourages the sugar to crystallise back into grains, so resist it. Pull the pan off the heat the moment the caramel reaches a deep amber, just short of where it smells like it might burn, because it carries on cooking in the residual heat and can tip from amber to acrid in seconds. Pour it straight over the toasted seeds, working quickly, and stand back; molten sugar sits at well over 150C and is unforgiving on skin, so never taste or touch it until it has set hard. Let it cool completely, then break it into shards with the base of a heavy pan or a rolling pin. If your caramel does seize into lumps rather than flowing smooth, return it to a low heat and let it slowly re-melt, without stirring, until liquid again.

One more note on toasting the sesame seeds for the brittle: do it in a dry pan over a medium heat, shaking constantly, for two to three minutes until they turn golden and smell nutty, then tip them straight out onto the tray so they do not carry on cooking. Pale, untoasted seeds give a flat, raw brittle; scorched ones turn bitter. That toasted-sesame aroma is the same thing you want from a good tahini sauce, and it is worth the couple of minutes of attention.

Getting the texture right

The single most important rule with blondies is to underbake them slightly. A blondie baked until firm all the way through is a flapjack with ambitions; a blondie pulled when the centre still wobbles is fudge with a cakey edge. Look for set, golden edges and a middle that looks barely done, then trust it to firm up as it cools. They are honestly better the next day, once the crumb has settled and the flavours have married.

Cool them completely in the tin before you even think about cutting. Warm blondies tear and crumble; cold ones slice into clean squares with a sharp knife wiped between cuts, and chilling the tin for half an hour first makes this easier still. Finish with flaky salt, which does the same job it does on a good chocolate chip cookie, sharpening the sesame and cutting through the butterscotch so the sweetness sings rather than sits heavy on the palate. Use a flaky sea salt like Maldon here rather than fine table salt, so you get distinct little bursts of salinity rather than an even background hum.

Substitutions, storage and make-ahead

Once you have the base, it flexes. Swap 65g of the plain flour for wholemeal to push the nuttiness further, or fold in 100g of chopped dark chocolate for the sesame-and-cocoa pairing that tahini brownies do so well. A tablespoon of black sesame paste rippled through the batter gives dramatic grey marbling and an even deeper, more mineral flavour. Pistachio halva in place of the vanilla adds colour and a resinous note; chocolate-marbled halva works too. If you cannot find halva at all, you can leave it out and add an extra 50g of tahini plus 25g of chopped toasted almonds, though you lose those melting seams that make the recipe.

For the tahini itself, buy a good jar and stir it thoroughly before measuring. A stone-ground tahini made from hulled sesame, often labelled as Lebanese, Palestinian or made from Ethiopian Humera seed, tastes nutty and smooth; a cheap, over-roasted one tastes acrid and will carry that bitterness into the bake. It is the same jar you would reach for to make herby falafel or a batch of tahini and date energy bars, so a good one earns its keep.

These keep exceptionally well and, as noted, improve overnight. Store them in an airtight container at room temperature for up to four days, or in the fridge for a week, where the crumb firms towards fudge. They freeze for up to three months, cut into squares and layered between sheets of baking paper; add the reserved brittle after thawing so it stays crisp rather than dissolving into the surface. You can make the sesame brittle up to two weeks ahead and keep it in an airtight jar somewhere dry, as it turns sticky in a humid tin. The blondie batter itself is best baked straight away once the raising agent is in, but you can weigh out and prepare everything else in advance.

However you tweak it, keep the brittle. Half melted into the top and half scattered crisp over the cooled tray, that glassy, caramelised crunch against the fudgy sesame crumb is the whole point.