Preheat the oven to 180℃/350℉. Line a baking tray with parchment/butter paper.
In a large bowl, beat butter on medium speed for 3 minutes or till the butter becomes creamy.
Add powdered sugar into the butter and beat on medium speed for 2-3 minutes or until a silky smooth consistency is achieved.
Sift in all-purpose flour, cornflour, and salt. Beat on low speed till all ingredients are combined and crumbs are formed.
With hands bring together the crumbs(do not knead) to form a dough.
Remove half of the dough (around 200 g) and place it in a small bowl. Add Nutella and 1 tbsp of all-purpose flour to the small bowl. Use a spatula to mix or use your hands to bring the crumbs together to form a dough.
Make small balls from both doughs (1½ tsp or 10 g each).
Combine a plain ball and a Nutella ball. You can combine these balls the way you want as we get different and distinct patterns. Roll them between the palm to form balls. Slightly press them flat.
9. Place them on the baking tray with little distance between them.
10. Bake in a preheated oven at 180℃/350℉ for 10-12 minutes or until the edges turn slightly golden.
11. After 10 minutes, place the cookies on a wire rack to cool completely before storing or serving.
