Rinse the lime under hot water, dab dry, grate the lime and lemon zest, mix with the flour, icing sugar, salt and vanilla in a bowl. Cut the butter into pieces, add to the bowl, rub together using your hands to form an evenly crumbly mixture. Beat the egg, add, mix quickly to create a soft dough, do not knead, cover and refrigerate for approx. 1 hr.
On a lightly floured surface, roll out the dough in batches to approx. 7 mm thick. Use the cutters to cut out bunnies or eggs. Place the biscuits on two baking trays lined with baking paper. .
Bake each tray for approx. 13 mins. in the centre of an oven preheated to 200°C. Remove from the oven, leave to cool on a cooling rack.
Mix the icing sugar with the lemon juice. Dip the surface of the biscuits in the icing, leave to dry for approx. 30 mins. Colour half of the remaining icing with yellow food dye and half with red food dye, transfer to separate disposable piping bags, cut off the tip of each bag, decorate the biscuits with dots and lines, leave to dry.