Heat the oven to 180°C
Sieve the flour into a bowl. Add the margarine and rub together between your fingers until it looks like fine breadcrumbs. Mix in the sugar and the beaten egg yolk. Knead until you obtain a soft dough.
Roll out the dough with a rolling pin. Cut out the shapes using bunny shaped cookie cutters. Put 2 silver balls on each cookie to make the eyes.
Carefully place the bunny shapes on greased baking paper and put in the oven for about 25 minutes or until the cookies get a light golden brown colour. Remove to a wire rack to cool.
Decorating: fill a piping bag with the pink icing and draw the nose and mouth of each bunny.