Fudgy Chocolate Tahini Swirl Loaf Cake (Marble & Moist)

Have you ever been curious about that nutty, slightly savory Middle Eastern spread called tahini? I was, for the longest time — until I drizzled it into a chocolate batter by accident, mid-recipe, while trying to thin out a too-thick ganache. The result was this cake. And I’ve been chasing that swirl ever since.

This chocolate tahini swirl loaf is the kind of bake that makes a quiet Tuesday feel like a small celebration. It is rich without being heavy, the crumb is tender and almost custardy in the middle, and the marbled top looks like it took way more effort than it did. If you have ever been scared of working with tahini in baking, please consider this your invitation. I will walk you through every step.

The Trick That Makes This Loaf So Good

Here’s the secret. The tahini does two things at once. First, it adds a deep, almost-roasted nuttiness that plays beautifully against the cocoa — the way sesame works in halva, but softer. Second, the natural oils in tahini replace some of the butter, which means we get a moist, almost-melty crumb without it feeling greasy. The swirl comes from gently folding chocolate batter and plain tahini batter together in the tin, then dragging a knife through once or twice. Don’t overwork it. You want ribbons, not mud.

Ingredients You’ll Need

• 130 g salted butter, softened, plus extra to grease the tin
• 120 g milk chocolate, roughly chopped (separated: 70 g for the batter, 50 g for the glaze)
• 220 g golden caster sugar
• 100 g tahini, well-stirred (a good runny brand — not the dry, separated kind)
• 3 medium eggs, room temperature
• 100 ml buttermilk
• 150 g self-raising flour
• 1 tsp baking powder
• 70 g halva, crumbled (optional but lovely)
• 2 tbsp cocoa powder (sifted)
• 50 g icing sugar, sifted
• 10 g golden syrup

A quick note on tahini: please, please stir it well in the jar before measuring. The solids sink to the bottom, and if you scoop from there, your batter will be dry and your cake will be heavy. You want it pourable, almost like a thick cream.

Here’s How I Bake It

Step 1: Heat the oven and prep the tin. Preheat to 180°C (160°C fan, gas 4). Grease a 900g loaf tin with butter and line it with a long strip of baking paper that hangs over the two long sides — this is how you will lift the cake out later without breaking the top.

Step 2: Melt the chocolate for the batter. Place 70 g of the chopped milk chocolate in a heatproof bowl over a pan of barely simmering water. Stir until smooth, then take it off the heat and let it cool a little while you do the next step.

Step 3: Cream the butter, sugar, and tahini. In a stand mixer (or with a hand whisk and a bit of patience), beat 100 g of the softened butter, the golden caster sugar, and the tahini together until smooth, pale, and fluffy. About three minutes on medium-high should do it. Scrape the bowl down once or twice.

Step 4: Add the eggs and buttermilk. Beat the eggs and buttermilk together in a small jug. Add this to the mixer in three additions, beating well between each. Don’t rush — you want the mixture to stay emulsified and smooth.

Step 5: Fold in the dry ingredients. Sift the flour and baking powder together, then gently fold them into the batter. Stop the second you cannot see any more flour streaks. Overmixing here is the fastest way to lose the tender crumb.

Step 6: Split the batter and flavor each half. Spoon roughly half the batter into a separate bowl. Stir the melted milk chocolate and the sifted cocoa into that half until evenly colored. Fold the crumbled halva into the plain tahini half. (If you are skipping the halva, just leave the plain half as is — it’s still gorgeous.)

Step 7: Swirl and bake. Dollop alternate spoonfuls of each batter into the lined tin — don’t try to spread them, just let them plop in. Once both are in, take a table knife and drag it through the batter two or three times in a figure-eight. That is your swirl. Slide into the oven for 50 minutes, or until a skewer comes out with just a few moist crumbs. Cover loosely with foil at the 35-minute mark if the top is browning too quickly.

Step 8: Cool and glaze. Let the cake cool in the tin for 10 minutes, then lift it out using the paper and transfer to a wire rack. For the glaze, melt the remaining 30 g butter with 50 g chocolate in short microwave bursts. Stir in the sifted icing sugar and the golden syrup, then loosen with about 20 ml of just-boiled water until it is pourable but not runny. Pour over the cooled cake and let it drip down the sides. Crumble the remaining halva on top.

Creative Twists Worth Trying

• Swap the milk chocolate for dark (70%) if you want a more grown-up, bittersweet version — and skip the halva crumble on top.
• Add a teaspoon of ground cardamom to the plain batter for a warm, almost-mysterious Middle Eastern note.
• Stir a handful of toasted sesame seeds into the chocolate half for a bit of crunch and visual texture.
• Drizzle the finished cake with extra tahini mixed with a little honey, instead of (or in addition to) the chocolate glaze.
• Bake it as a round 20 cm cake instead of a loaf — increase the bake time by 5–10 minutes and check with a skewer.

Serving & Pairing Ideas

This is one of those rare bakes that works for nearly any moment. For breakfast, a thick slice with strong black coffee and a smear of salted butter. For afternoon tea, a thinner slice with a cup of Earl Grey. For dessert, warm a slice very gently (10 seconds in the microwave) and serve with a small scoop of vanilla ice cream or a spoon of cold crème fraîche. A small glass of sweet dessert wine, like a Muscat, is a surprisingly lovely match if you are doing this for friends.

Storage & Make-Ahead Tips

The cake keeps beautifully in an airtight tin at room temperature for 3 to 4 days — the tahini keeps it moist. If you want to bake ahead, the unglazed loaf freezes really well. Wrap it tightly in baking paper, then foil, and freeze for up to three months. Defrost at room temperature still wrapped, then glaze on the day you want to serve. I do not recommend refrigerating — the crumb dries out faster in the fridge than on the counter.

Common Mistakes & Easy Fixes

• The swirl looks muddy, not marbled. You overworked it. Next time, drag the knife through only once or twice, in long confident strokes.
• The cake is dry. Two likely causes: tahini wasn’t stirred before measuring, or the cake was baked too long. Pull it out when the skewer still has a few moist crumbs — it’ll finish setting as it cools.
• The top cracked open dramatically. That’s actually a sign of a good rise! But if you’d rather a flatter top, lower the oven by 10°C and bake a touch longer.
• The tahini flavor is too strong. Try a milder, runnier brand (the Lebanese or Israeli ones are usually smoother and less bitter than some supermarket versions).

Your Tahini Loaf Questions, Answered

Can I make this without halva? Absolutely. The halva is a garnish for texture and a bit more sesame flavor. The cake is just as good without it.

Can I use natural peanut butter instead of tahini? It will not be the same cake — peanut butter is sweeter and more assertive — but yes, you can substitute it in equal weight for tahini if that’s what you have. The swirl will be more like a peanut butter cup, which is also delicious.

Is this cake very sweet? It’s sweet, but the tahini and the salt in the butter keep it from being cloying. If you’re sensitive, drop the sugar to 180 g and skip the glaze.

Can I bake it in muffin tins instead? Yes — about 20 minutes at the same temperature, checking early. They freeze beautifully and make wonderful lunchbox treats.

What if I don’t have buttermilk? Stir a tablespoon of lemon juice or white vinegar into 100 ml of whole milk, let it sit for five minutes, and use that. Or use plain kefir, thinned with a splash of milk.

Can I make it gluten-free? A good 1:1 gluten-free flour blend (with xanthan gum already in it) works well here. Let the batter rest for 10 minutes after mixing before baking — it gives the GF flours a chance to hydrate.

A Little Goodbye from My Kitchen

This loaf is the kind of thing I make when I want my kitchen to smell like something good is happening — and trust me, it will. The tahini, the butter, the milk chocolate melting together — it’s a smell that pulls people in from other rooms, and that is always a good sign.

If you make it, I would love to hear how it turned out. Did you swirl boldly or keep it neat? Did you go for the halva on top? Drop a comment and let me know — and if you tag me on socials, I will absolutely swoon over your photos.

Until next time, happy baking.
—Marina Caldwell