Jenny's guide to buying and storing walnuts: The inside of the walnut kernel should be a creamy colour, not opaque, which indicates old nuts and rancidity. The outside skin should have a shine and ...

Top each one with a walnut kernel if you like. Bake for 20–25 minutes, or until the muffins come away from the side of the pan when touched. Rest the muffin tray on a wire rack for 5 minutes ...