Preheat your oven to 325 degrees Fahrenheit and prepare a large baking sheet by lining it with parchment paper.
Whip the butter on high speed in the bowl of your stand mixer fitted with the whisk attachment, or in a large bowl using a hand mixer.
When the butter has turned a pale yellow colour and has achieved a super smooth texture, beat in the powdered sugar until well combined.
Add the flour, cornstarch and vanilla and whip on high speed for about 4-5 minutes or until the dough has completely come together and developed a light and airy texture, and is almost white in colour.
Drop by the teaspoonful onto a baking sheet lined with parchment paper and press some of the candied fruit into the top of each cookie.
Bake for 10-12 minutes at 325 degrees Fahrenheit or until the cookies lose their sheen. Be sure to remove them from the oven before the edges begin to brown, so make sure to watch them carefully for the last 2 to 3 minutes they're in the oven (Every oven is different, so this is good practice just to be safe!).
Let them cool on the pan until they cool to room temperature and enjoy with some delicious homemade hot chocolate, your favourite latte, or a cup of tea!