100 g (3 1/2 oz) mixed dark, milk and white chocolate chips
4 scoops of vanilla ice cream
Line a baking sheet with greaseproof paper. Beat the butter and sugars until light and fluffy, then stir in the egg. Beat in the flour, baking powder and vanilla extract, then stir in three-quarters of the chocolate chips.
Use a teaspoon to dollop 24 walnut-sized balls of dough, well spaced apart, on to the baking sheet and flatten gently. Scatter with the remaining chocolate chips and cook in the preheated oven, 190°C (375°F), Gas Mark 5, for 8–10 minutes until golden and just cooked through.
Leave the cookies to cool on a wire rack, then serve 2 to each person, sandwiched together with a scoop of vanilla ice cream.