Equipment
Ingredients
Dusting Powder
- 60 g powdered sugar
- 60 g cornstarch
Raspberry Coulis
- 200 g raspberries, fresh or frozen
- 30 g granulated sugar
- 15 ml lemon juice
Gelatin Bloom
- 21 g unflavored gelatin powder
- 120 ml water, ice cold
Sugar Syrup
- 400 g granulated sugar
- 225 g light corn syrup
- 120 ml water
- 2 g kosher salt
Flavoring
- 10 ml vanilla extract
Nutrition (per serving)
Method
Sift the powdered sugar and cornstarch together in a small bowl to create the dusting powder.
Lightly oil the 20x20cm baking pan, then coat the bottom and sides generously with a portion of the dusting powder, tapping out any excess.
Combine the raspberries, 30g granulated sugar, and lemon juice in a small saucepan. Simmer over medium heat until the berries completely break down and release their juices.
Pass the hot raspberry mixture through a fine mesh sieve into a clean bowl, pressing firmly with a silicone spatula to extract all the liquid and discard the seeds.
Return the strained raspberry juice to the saucepan and reduce over low heat until it becomes a very thick, jam-like paste. Transfer to a small bowl and cool completely.
Place the 120ml cold water in the bowl of the stand mixer. Sprinkle the gelatin powder evenly over the surface and let it bloom undisturbed.
In a medium saucepan, combine the 400g granulated sugar, light corn syrup, 120ml water, and kosher salt. Boil over medium-high heat without stirring until the mixture reaches 115°C/240°F on a candy thermometer.
Turn the stand mixer on low speed. Carefully and slowly pour the hot sugar syrup down the side of the mixer bowl into the bloomed gelatin.
Once all syrup is added, gradually increase the mixer speed to high. Whip until the mixture is exceptionally thick, pure white, glossy, and the bowl feels lukewarm to the touch.
Add the vanilla extract during the final minute of whipping, folding it in until just combined.
Working quickly, scrape half of the marshmallow mixture into the prepared pan using an oiled silicone spatula. Drop spoonfuls of half the cooled raspberry reduction over the surface.
Top with the remaining marshmallow mixture and the rest of the raspberry reduction. Use a wooden skewer to vigorously swirl the layers together, creating a marbled effect.
Dust the top of the marshmallows with a light layer of the dusting powder. Let the pan rest uncovered at room temperature to cure and set.
Turn the set marshmallow slab out onto a cutting board dusted with powder. Slice into squares using a chef knife lightly coated in oil, then toss all sticky edges of each square in the remaining dusting powder.
Chef's Notes
- Reducing the raspberry puree heavily is non-negotiable. Any extra water introduced to the marshmallow base will actively dissolve the matrix, resulting in sticky, unstable pockets.
- When cooking the sugar syrup, do not stir it once it reaches a boil. Stirring encourages crystallization. If sugar crystals form on the sides of the pan, brush them down with a wet pastry brush.
- Do not scrape the bottom of the saucepan when pouring the hot syrup into the mixer. Any crystallized sugar left at the bottom of the pot could seed the entire batch and ruin the smooth texture.
- Marshmallow is notoriously sticky. Lightly oil your silicone spatulas and your knife with a neutral oil before handling the mixture to make the process completely frictionless.
Storage
Refrigerator: 2 weeks — Store in an airtight container layered with parchment paper. Bring to room temperature before serving for best texture.
