Make sure you measure the amount of carrots without the skin and ends. Cut them in thin slices. They don't need to be completely even as we're going to process them afterwards, but of course smaller cuts means less cooking time. Boil for 20-30min or until it's REALLY soft.
Rinse the carrots in cold water to bring them to room temperature. This is important because if they're hot they will melt the butter.
Use a food processor or hand blender to mix together the carrots, butter, sugar and salt. Make sure to scrape the sides of the bowl so there are no lumps of carrots left.
Add the vanilla essence and finish with the flour. Mix using a spatula.
Put the mix in a piping bag with a star nozzle and pipe the cookies on top of an oven tray lined with a silicone mat or baking paper. You can make rings like me or strips, hearts, or any shape you like.
Place them in a preheated oven at 180°C/350°F 10-15min or until you lift them and they're slightly golden underneath.
Let them cool down completely before applying the glaze.