Preheat oven to 180°C. Line a baking tray with baking paper.
Using electric beaters, beat butter, caster sugar and lemon rind in a large bowl until light and creamy. Add egg and continue beating until fully combined. Mix through flour and macadamias.
Roll a tablespoon of mixture into a rough ball and place on baking tray, press down slightly to flatten. Continue with remainder of mixture.
Bake for 15 minutes or until golden.
TIP: Substitute lemon rind for 1 teaspoon of ground ginger or ½ teaspoon of ground cinnamon for a macadamia spice flavoured cookie.
