Crispies appeal to all ages, so much so that Grandma encountered them at the local three starred restaurant when she lived in France. Crispies are made with cereal stuck together with melted chocolate and then drizzled with more white and dark chocolate (the first time Lucy made them, she was drizzled with chocolate too). In the US, Mars bars are known as Milky Ways.

Makes 16 crispies
3 cups/90 g/3 oz rice crispies
4 Mars bars (40 g/1 1/4 oz each)
1/2 cup/125 g butter, diced, more for the baking sheet
2 3 oz/100 g chocolate bars, one dark, one milk (for decoration)

1. Line a baking sheet with parchment paper. Put the rice crispies in a large bowl. Cut the Mars bars in chunks and put them in a saucepan with the butter. Warm over low heat, stirring often with a wooden spoon, until the mixture is melted and bubbling, 3-5 minutes.

2. Pour the mixture into the rice crispies, stirring with a large spoon. While still warm, spread this on the baking sheet as an 8-inch/18-cm square about ¾ inch/2 cm thick, flattening the top with the spoon and straightening the edges. Leave to set, at least 8-10 minutes.

3. For decoration: heat a small saucepan of water until almost boiling. Break one of the chocolate bars into squares, put them in a heatproof bowl and set it over the steaming water. Heat until the chocolate is melted, stirring occasionally, 5-7 minutes (don’t let any steam get into the chocolate). With a fork, drizzle the melted chocolate over the crispie mixture in fine trails and leave to set, 8-10 minutes. Repeat with the other chocolate bar to make a dark and white chocolate lattice. You will have some chocolate left over. Chill the decorated slab of crispies until firmly set, at least 30 minutes.

4. Trim the edges of the mixture with a large heavy knife (the trimmings are the cook’s reward). Cut it in 2-inch/5-cm squares. Store the crispies in an airtight container, layered with parchment paper or plastic wrap. They will keep for up to a week.