1 Heat the oven to 180°C (160°C in a fan oven), 375°F, gas 5 and line a cake tin (approx. 21x21 cm) with grease-proof paper.
2 Beat 225 g butter with the sugar until creamy. Sieve over the flour and mix to a smooth dough. Press into the cake tin and bake for around 20 minutes until golden. Remove from the oven and leave to cool.
3 For the caramel layer, heat the remaining butter. Stir in the condensed milk and honey and bring to the boil. Simmer for around 50 minutes, stirring regularly, until golden brown and caramelised. Pour over the base and leave to cool, then chill for around 30 minutes.
4 Melt the chocolate in a bowl over hot water. Cool slightly then pour over the caramel. Smooth flat then chill for at least 3 hours until completely cool.
5 Use a sharp knife to cut into small squares before serving.