Put the fat and syrup into a heavy saucepan and warm until the fat has melted. Remove from the heat and mix in the bicarbonate of soda and vanilla essence, then beat in the flour. Cool.
Roll out the mixture until wafer thin and cut into shapes with biscuit cutters. Place on greased baking sheets and bake in a cool(300F) oven for 40 minutes or until golden brown. Cool on a wire rack.