Serves: approximately 9 dozen marshmallows1) To prepare the tin: Combine the icing sugar and cornflour in a small bowl. Lightly brush a metal baking pan (33 by 23-cm) with vegetable oil. Add the sugar and cornflour mixture and move around to completely coat the bottom and sides of the pan. Return the remaining mixture to the bowl for later use.
2) For the marshmallows: Place the gelatine into a medium bowl with 120ml of the water. In a small saucepan combine the remaining 120ml water, granulated sugar, golden syrup and salt. Place over medium high heat, cover and allow to cook for 3 to 4 minutes.
3) Uncover the pan and clip a sugar thermometer onto the side. Continue to cook until the mixture reaches 115 degrees C, approximately 7 to 8 minutes. Once the mixture reaches this temperature, immediately remove from the heat.
4) With a hand held mixer on low speed, slowly pour the sugar syrup down the side of the bowl into the gelatine mixture. Once you have added all of the syrup, increase the speed to high. Continue to whisk until the mixture becomes very thick and is lukewarm, approximately 12 to 15 minutes. Add the vanilla during the last minute of whisking.
5) When ready, pour the mixture into the prepared pan, using a lightly oiled spatula to spread evenly. Dust the top with enough of the remaining sugar and cornflour mixture to lightly cover. Reserve the rest for later. Allow the marshmallow to sit uncovered for at least 4 hours and up to overnight.
6) Turn the marshmallow out onto a cutting board and cut into 2.5-cm squares using a pizza wheel dusted with the icing sugar mixture. Once cut, lightly dust all sides of each marshmallow with the remaining mixture, using additional if necessary. Store in an airtight container for up to 3 weeks.
7) For miniature marshmallows: Combine the icing sugar and cornflour in a small bowl. Line 4 baking trays (46 by 33-cm) with non-stick baking paper. Brush the paper lightly with oil and dust with the icing sugar mixture.
8) Scoop the mixture into a piping bag fitted with a 2.5-cm round piping nozzle. Pipe the mixture onto the prepared trays lengthwise, leaving about 2.5-cm between each strip. Sprinkle the tops with enough of the remaining cornflour and sugar mixture to lightly cover. Let the strips set for 4 hours or up to overnight.
9) Cut the strips into 1-cm pieces using a pizza wheel or kitchen scissors dusted with the icing sugar mixture. Lightly dust all sides of each marshmallow with the remaining sugar mixture and store in an airtight container for up to a week.