Raspberry Sherbet and Scorched Marshmallow Floats

Thaw the raspberries with their juice then tip into a food processor.

Add the icing sugar and citric acid and process until smooth.

Strain the purée through a fine sieve set over a bowl, pressing until only the seeds remain. Discard the seeds. Chill the purée until ready to use. 

Marshmallow: Whisk the egg whites and cream of tartar in a standing mixer until soft peaks form. 

Put the water, sugar and glucose or rice syrup in a small saucepan over a medium heat, stirring to dissolve the sugar. When boiling, cook for 3 minutes to make a syrup. 

With the mixer running, slowly pour the hot syrup into the egg whites, then add the vinegar and vanilla. Beat for about 5 minutes until very thick and glossy and the marshmallow is cool. 

To assemble: Place scoops of ice cream into glasses and pour about ¼ cup of chilled raspberry purée over each one. Add fresh raspberries if using and carefully add enough soda to come about 2cm below the top of the glass. Add large dollops of marshmallow and swirl the top to form peaks. Brown the tops with a kitchen blowtorch or leave plain. Serve immediately. Makes 6 floats

Pantry Note: Citric acid can be found in the baking aisle in supermarkets. It adds a tart, fizzy taste to the raspberries and is one of the ingredients used to make sherbet.