S’mores Tart - Chocolate Raspberry Marshmallow Tart
Look, I think the hero of my chocolate raspberry marshmallow tart recipe is the raspberry jam—particularly my low sugar raspberry jam. But I’ve had some pushback on that from my kids—adult kids, mind you. They say, “You’ve got to come clean, Mum. You’ve got to admit this is really your version of a s’mores tart.” And I say, “Come on, how is that going to fly with my decidedly Australian and New Zealand audience?” So, in what was truly a watershed moment, Mum compromised—and I renamed this recipe to my S’mores Tart – Chocolate Raspberry Marshmallow Tart.
Equipment
- Food processor
- 36cm x 13cm fluted non-stick rectangular tart tin (or 23–25cm round loose-bottom tart tin)
- Silicone baking mat
- Offset spatula (small)
- Stand mixer with whisk attachment
- Digital thermometer
- Immersion blender
- Large piping bag with star tip (optional)
- Blowtorch (hardware-store strength recommended)
Ingredients
- 350 g HobNob biscuits (or similar)
- 150 g unsalted butter no. 1 (115g brown butter)
- 200 g low sugar raspberry jam
- 300 g dark chocolate (75%)
- 340 g pure cream (minimum 35% fat)
- 40 g glucose no. 1
- 40 g unsalted butter no. 2
- ¾ teaspoon sea salt
- 240 ml water
- 15 g gelatine powder
- 340 g granulated white sugar
- ½ teaspoon table salt
- 165 g glucose no. 2
Instructions
Assemble ingredients and equipment
- This recipe moves through several steps and layers, so having everything measured out and ready will make the whole process smoother.
Make the brown butter
- In a wide-bottomed stainless steel pan, melt 150g unsalted butter over medium-high heat.
- Cook, stirring occasionally, until the milk solids turn golden brown and it smells nutty and toasted.
- Pour into a heatproof jug and set aside to cool slightly.
Make the biscuit base
- In a food processor, blitz 350g HobNob biscuits (or similar) to a fine crumb.
- While pulsing, gradually add 115g of the brown butter until the mixture reaches a wet sand consistency and clumps when squeezed.
- Press the mixture into a lined tart tin, starting with the sides and finishing with the base.
- Use a small offset spatula or a measuring cup to smooth and tamp it down.
- Freeze for 15–20 minutes, then bake at 175°C conventional (155°C fan) for 15 minutes.
- Cool completely, then return to the freezer until ready to assemble.
Add the raspberry jam layer
- Pipe or spoon 200g raspberry jam onto the cold tart base and smooth with a small offset spatula. Keep the tart in the fridge while you make the ganache.
Make the ganache
- Place 300g chopped dark chocolate and 40g unsalted butter in a tall heatproof jug.
- In a saucepan, bring 340g cream to a boil and pour it over the chocolate and butter. Let sit for 5 minutes.
- Add 40g glucose and ¾ teaspoon sea salt (finely ground).
- Blend with an immersion blender until glossy and smooth. Keep the blender at the bottom to avoid introducing bubbles.
- Pour the ganache into the tart shell over the jam layer. Use an offset spatula to gently nudge it into the corners, then tap the tin on the bench to release any air bubbles.
- Chill uncovered for at least 4 hours or overnight.
Make the marshmallow
- In the bowl of a stand mixer, add 120ml room temperature water and sprinkle over 15g gelatine.
- Set the mixer on low with the whisk attachment.
- In a medium saucepan, combine 120ml water, 340g sugar, 165g glucose, and ½ teaspoon salt.
- Bring to a boil and cook until the syrup reaches 122°C.
- Carefully pour the syrup down the side of the mixing bowl, gradually increasing mixer speed to high.
- Beat for 13 minutes until thick, fluffy, and forming stiff peaks.
Top the tart with marshmallow
- If piping, transfer the marshmallow to a prepared piping bag.
- Let the marshmallow set for a few minutes. Test with a small piped amount or a spoonful onto a plate. If the marshmallow holds its shape, it's ready to go. Otherwise, wait a minute and test again.
- For a freeform style, dollop it onto the tart and use an offset spatula to swirl into peaks. Work quickly before the marshmallow sets.
- Limit height to no more than three times the ganache layer.
Torch the marshmallow
- Use a blowtorch to toast the marshmallow, moving the flame across the surface at varying angles.
- Aim for golden swirls with a few darker tips for that signature campfire finish.
Just before you cook with abandon…
What’s the difference between a biscuit and a cookie? Honestly? It depends on where you grew up. In Australia, the UK, and New Zealand, a biscuit is what Americans would call a cookie—crunchy, snappy, and made for dunking in tea. In the US, a biscuit is something else entirely—a soft, buttery bread roll usually served with stew. Confusing? A little. But if you grew up calling it a biscuit, it’s a biscuit. We’re not here to start an international incident—just to make dessert.
Beurre noisette, explained Beurre noisette, or brown butter, is just regular butter that’s been melted and cooked until the milk solids toast and turn golden brown. It adds a deep, nutty aroma and flavour that gives even the simplest bakes a more complex, toasty richness. Use a wide pan, don’t walk away, and pour it out as soon as it turns golden—you’re aiming for toasted, not burnt.
Choosing chocolate for ganache Baking chocolate is your best bet for silky, stable ganache. I recommend Callebaut 70% callets if you want to go luxe, or Nestlé Plaistowe 70% for a more budget-friendly option. Avoid eating chocolate if you can—brands like Lindt Excellence 70% or Old Gold (approx. 45% cocoa solids) can work in a pinch but may split or behave unpredictably when melted.
Using an immersion blender for ganache An immersion blender creates a smooth, glossy ganache without whipping in excess air. Keep the head of the blender at the bottom of the jug and blend gently. If you don’t have one, skip the whisk and use a spatula or wooden spoon to stir vigorously without aerating the mixture.
Getting marshmallow texture just right Marshmallow can go from fluffy to unworkable in minutes. Wait a few minutes after whipping, then test a spoonful or piped dollop on a plate. If it holds its shape, it’s ready. Too soft? Wait and test again. Too firm? You’ll know—because it won’t budge from the bowl.
What to do with leftover marshmallow? The recipe makes a generous amount of marshmallow to ensure it whips and sets properly. Have a baking paper–lined tray ready for the extra. Once it sets, cut it into pieces and toss with cornflour or a mix of cornflour and icing sugar to keep them from sticking. You’ve got bonus marshmallows—never a bad thing.
Jam substitutions Homemade low sugar raspberry jam adds sharpness and contrast to the richness of the ganache, but you can use store-bought jam if time is tight. Choose one that’s not too sweet—something with bold berry flavour and good acidity. Blackcurrant or sour cherry would also work beautifully in place of raspberry.
Storage and slicing This tart keeps well in the fridge for up to 3 days. Use a sharp knife dipped in hot water and wiped dry between slices to get clean layers without dragging the marshmallow.