Keep the egg on the countertop for 3-4 hours to bring it to room temperature.
I forgot to bring my butter to room temperature and melted it in the microwave for 1 minute.
Measure all the ingredients and keep them aside.
Mix together flour, baking powder, salt and keep it aside.
Preheat the oven 350 F.
In bowl beat butter and sugar until creamy & fluffy. With my electric hand held mixer, it took 2 minutes.
Add egg and continue to beat for few seconds until egg is incorporated into butter sugar mixture.
Add lime rind, grated zucchini and mix well.
Now fold in the flour little at a time. I set my mixer to fold and added 2-3 teaspoons of flour at a time. Fold in all the flour.
Using two teaspoons, make round balls of the dough and drop on to the cookie sheet. I had to bake in two batches. I popped the first tray in the oven and then shaped the rest of the dough for the second batch.
Bake the cookies in the pre-heated oven for 14 – 16 minutes until the edges are golden brown. Mine were done in 15 minutes and cookies were soft. For crispy cookies, bake for another minute. Do remember oven temperatures vary from oven to oven.
Remove from the oven and let the cookies cool for couple of minutes on the tray. Then transfer to a wire rack and let cool completely.
Store the cookies in an airtight container.