1.Preheat oven to 150°C. Grease an 8-hole (180ml) mini loaf pan and line bases with baking paper.
2.Beat butter, rind, sugar, eggs, flour and milk in a medium bowl with electric mixer, on low speed, until combined. Increase speed to medium; beat about 3 minutes or until mixture is light and fluffy.
3.Divide mixture among pan holes and cover pan loosely with foil. Bake about 25 minutes. Stand cakes 5 minutes. Turn, top-side up, onto wire rack to cool.
4.To make lime ganache, stir chocolate, juice and cream in small heatproof bowl over small saucepan of simmering water until smooth. Refrigerate until spreadable.
5.Split loaves in half. Sandwich loaves with half of the ganache and half of the pineapple. Top loaves with remaining ganache and pineapple.