120 g/4 oz butter at room temperature, plus extra for greasing
250 g/9 oz light brown sugar, plus extra for dipping
120 g/4 oz soft margarine
2 eggs, lightly beaten
2 tsp vanilla extract
350 g/12 oz plain flour
1/2 tsp bicarbonate of soda
225 g/8 oz salted peanuts
Preheat the oven to 190°C/375°F/Gas Mark 5. Grease 2 baking sheets with butter and also grease the base of a tumbler. Dip the base of the tumbler in brown sugar.
Cream the butter, margarine and sugar until light and fluffy. (An electric mixer makes this process quick and easy, but otherwise use a wooden spoon.)
Beat in half the egg, then the vanilla extract, then the remaining egg.
Sift together the flour and bicarbonate of soda, in batches, over the mixture and gently fold in.
Gently stir in the peanuts until all the ingredients are combined.
Take teaspoonfuls of the mixture and drop them on the prepared baking sheets, spacing them about 5 cm/2 inches apart. Gently flatten with the base of the prepared tumbler, greasing and dipping in the sugar again as necessary.
Transfer the baking sheets to the oven and bake for 10–12 minutes, until lightly golden. Remove from the oven and transfer with a palette knife to wire racks to cool completely.