Beat butter, extract and sugars in small bowl with electric mixer until light and fluffy. Add eggs, one at a time, beating until just combined. Transfer to large bowl.
Stir combined sifted flour, soda and nutmeg, in batches, into the egg mixture. Cover and refrigerate dough 30 minutes.
Preheat oven to 180°C / 160°C fan-forced. Line oven trays with baking paper.
Combine extra caster sugar and cinnamon in a small shallow bowl. Roll level tablespoons of the dough into balls; roll balls in cinnamon sugar. Place balls about 7cm apart on oven trays.