Heat the oven to 160C

Grease to baking sheets or cut baking parchment to fit

Beat together the margarine and sugar until creamy, then work in the egg and vanilla extract.

Add the oats and flour and work until you have a soft dough.

Divide the mixture into about 20 pieces and roll into balls, you might find this easier if you slightly wet your hands.

Roll the cookie dough balls in rolled oats and place 5 cm (2in) apart on the baking sheets. Flatten each piece of dough and place a chunk of dark chocolate in the centre of each.

Bake in the oven for 20 minutes or until the biscuits are pale golden brown.

Cool on a wire rack