2 Bring butter, honey and sugar to a boil in a large skillet.
3 Squeeze juice from lime half.
4 Stir 1 tablespoon lime juice, oats, amaranth, almonds and pineapple into the butter mixture.
5 Spread the mixture with a moistened rubber spatula until about 2 cm (approximately 1 inch) thick on a parchment-lined baking sheet and bake on middle rack of preheated oven at 150°C (fan 130°C, gas: mark 1-2) (approximately 300°F) for 15-18 minutes.
6 Cut into bars while still warm and let cool before serving or storing in airtight containers.