• 400g caster sugar
  • 1 tablespoon golden syrup
  • 300ml water, divided
  • 4 tablespoons unflavoured powdered agar-agar or gelatine
  • 2 egg whites
  • 1 teaspoon vanilla extract
  • food colouring (optional)
  • 125g icing sugar for dusting
  1. Line a 22cm square cake tin with cling film and dust with icing sugar
  2. Place 125ml water in a heatproof bowl and sprinkle the agar-agar, heat over a pan of boiling water until it has completely dissolved. Remove the pan from heat but keep the bowl on top to stop the it from solidifying
  3. In a medium saucepan, mix the caster sugar, golden syrup and 175ml of water over a medium heat. Heat to 125C (until a small drop of the mixture forms a soft ball when dropped into cold water)
  4. Turn off the heat and pour in the agar-agar while whisking
  5. Whisk eggs whites to stiff peaks, pour in the hot mixture slowly while whisking continuously. Beat until the mixture is very stiff.
  6. Stir in the vanilla and food colouring (if using) and spread evenly into the cake tin
  7. Leave to set (not in the fridge) overnight before cutting and rolling in icing sugar. Store in an airtight container for up to a week