Preheat the oven to 190°C. Line a baking tray with baking paper.
Cream the butter, sugar and vanilla together until light and fluffy. Add the egg, beating well. Sift the flour and baking powder together and mix into the creamed mixture.
Roll heaped teaspoons of mixture into balls and place on the prepared tray. Flatten slightly with a floured fork.
Bake for about 12 minutes or until pale golden. Leave on tray for 1-2 minutes then place on a wire rack to cool.
You can also shape the biscuit dough into a log, wrap it in waxed paper or tinfoil and chill it for an hour or so, then slice into discs for baking. the dough will also keep in the freezer for 1 month.
Chocolate Biscuits Add 2 tablespoons cocoa when sifting flour.
Orange Biscuits Replace vanilla essence with 1 tablespoon grated orange rind in creamed mixture.
Lemon Biscuits Replace vanilla essence with 2 teaspoons finely grated lemon zest in creamed mixture
Spice Biscuits Add 2 teaspoons mixed spice when sifting flour.
Sultana Biscuits Fold ½ cup sultanas into creamed mixture.