Shortbread Crumble Slice

Based on one of New Zealand’s wonderful traybakes, Tan Slice, this has a vanilla shortbread base, a layer of sticky toffee and a crunchy crumble topping. Delicious, and perfect for an island picnic on the beach, whether huddled in sweaters behind a windbreak with a thermos of hot coffee — or lying on the clean white sand in shorts, watching the cows stroll along the shore on a sun-kissed warm day.