540g/1lb 4oz gluten free plain flour, plus extra for dusting
2 tbsp cocoa powder
For the marshmallow filling
180g/6¼oz granulated sugar
170ml/5¾fl oz liquid glucose
pinch fine salt
2 large free-range egg whites
1½ tsp vanilla bean paste
Serves - 6
Preheat the oven to 180C/170C Fan/Gas 4. Grease two baking trays and line with parchment. Put the lactose free butter, orange zest and orange blossom water in a free-standing mixer and mix until soft. Add the sugar and beat until light and fluffy. Add the gluten free flour, cocoa and bring the mixture together with your hands.
Generously flour a work surface and roll the dough to 5mm/¼in thick. Use a cutter to cut out 48 star shapes. Use a palette knife to transfer the shortbread to the prepared baking trays. Prick each star with a fork and place in the fridge for 15 minutes.
Bake for 15 minutes, or until golden brown. Leave to cool on the tray for 5 minutes before transferring to a wire rack.
For the marshmallow filling, put the sugar, liquid glucose, salt and 2½ tablespoons water in a small, heavy bottomed saucepan. Place over a high heat and stir until all the sugar has dissolved.
Use a sugar thermometer to monitor the temperature, once it has reached 115C remove from the heat (Caution: boiling sugar is extremely hot. Handle very carefully).
Whisk the egg whites and vanilla bean paste in a free-standing mixer until they form soft peaks. With the whisk going, add 2 tablespoons of the sugar syrup. Gradually add the rest of the syrup and continue to beat for about 5 minutes, or until a stiff consistency is achieved. Pour into a piping bag and place in the fridge.
To assemble, pipe the marshmallow into the middle of a shortbread and use a blowtorch to brown. Gently place another shortbread on top to make a sandwich. Repeat this process with the remaining shortbread and marshmallow to make 24 sandwiches.