Beat the butter and sugar together in a large bowl, till light and fluffy. Beat in the egg and the extracts and the lime zest. Sift together the flour, corn-starch and the salt. Mix this in till you have a smooth dough. Do not overwork the dough.

If the dough seems crumbly and dry, add a little milk, a tbsp. at a time, just enough to form a dough. Do not add too much so it becomes sticky. Shape into a ball and wrap in cling film. Refrigerate for at least 4 hours or overnight.

When ready to make the cookies, turn out the dough onto a lightly floured work surface. Sprinkle a little flour on the dough (not too much or you’ll have tough cookies) as well. Knead the dough gently so it is pliable. Divide the dough into 2 or 4 pieces. Work on one piece and keep the others covered and in a cool place.

Roll the dough out to about a 1/8 inch thickness. If you do this on a piece of baking parchment, the cookies will be easier to lift off and transfer to the baking sheet. Dip your cookie cutters in flour and cut out cookies. Transfer the cut out cookie dough to ungreased or parchment lined baking sheets.

Place the scraps on top of each other and roll out and cut cookies. Repeat with remaining dough.

Bake the cookies at 180C (350F) for about 10 to 15 minutes till they start browning on the edges. Cool completely and transfer to an airtight tin till ready to decorate them.

Make the Royal Icing by beating the egg whites till just frothy. Beat in the lime juice and then the icing sugar, a cup at a time, till smooth. This consistency is perfect for dipping the cookies and doesn’t need to be diluted further. Always store extra Royal Icing in an airtight container in the fridge.

Put about 2 tbsps of the Royal Icing each into two small bowls. Add a couple of drops of different shades of blue (I used Baby Blue and Royal Blue) in each bowl and mix well. You can put this into piping bags or drizzle them with tablespoons. I found the piping bags easier and less messy.

Put about 6 tbsps of the white Royal Icing in a wide and shallow bowl. Put the remaining Royal Icing in an airtight container and refrigerate for later use. Royal Icing will crust and harden quickly otherwise.

Cut the tips (small holes) on the bags and pipe or drizzle some of both the coloured icings randomly on the surface of the white Royal Icing in the shallow bowl. Dip each cookie carefully (see the video in the link mentioned earlier), and let the excess icing fall off. If the excess falls off you will have very few drips later on. Place on a rack and let the icing dry.

Once you have dipped a few cookies (4 or 5) you might find the colours fading. If so, pipe or drizzle some more of both the coloured icings again. Then dip the remaining cookies this way. You can decorate the cookies further with sprinkles, dragees or lustre dust if you wish.

The cookies will need about 4 to 5 hours to dry completely, depending on the humidity where you are. Then pack them in airtight containers.