Line 2 baking sheets with nonstick baking paper. Place the butter, vanilla paste or extract and 150 g (5 oz) of the sugar in a bowl and beat together with a hand-held electric whisk until light and fluffy. Add the egg and beat well, then stir in the chopped nuts. Sift in the flour, cream of tartar, baking powder, 1 teaspoon of the cinnamon, the nutmeg and salt and stir until combined.
Mix the remaining cinnamon and sugar in a small bowl and sprinkle over a plate. Roll the dough into 18–22 walnut-sized balls, then roll them in the cinnamon sugar to coat. Place, well spaced apart, on the prepared baking sheets and flatten slightly.
Bake in a preheated oven, 200°C (400°F), Gas Mark 6, for 12–15 minutes until firm. Leave to cool on the baking sheets for 2 minutes, then transfer to wire racks to cool completely.