Hazelnut Brittle is a traditional British recipe for a classic sweet (candy) of hazelnuts set in a hard sugar toffee. The full recipe is presented here and I hope you enjoy this classic British version of: Hazelnut Brittle.
Combine the sugar, syrup, water and butter in a large heavy-bottomed saucepan. Bring this mixture to a boil over moderate heat, stirring constantly with a wooden spoon until the sugar has completely dissolved. Boil for 3 minutes then continue to cook until the mixture reaches 115°C, as measured with a confectioner's thermometer. Add the hazelnuts then cook over moderate heat with constant stirring until the mixture reaches 150°C (300°F/Gas Mark 2) on a sugar thermometer.
Be careful at this stage that the mixture does not burn. Remove the pan from the heat and quickly add the vanilla and baking powder, stirring constantly. Immediately pour the mixture onto a buttered baking sheet and spread evenly. Lift and pull the mixture with two forks to form a rectangle. Pull gently at this stage to prevent tearing. Transfer to a wire rack and allow to cool completely then break into pieces.