Beat the sugar and softened butter with electric beaters or a stand mixer until light and fluffy.If using a Thermomix: Cream the butter and sugar for 20 seconds, Speed 4. Scrape down the sides of the bowl and repeat for a further 20 seconds, Speed 4.
Add the egg and continue to mix until combined.If using a Thermomix: Add egg and mix for 10 seconds, Speed 4.
Sift in the plain flour and baking powder. Stir gently to combine.If using a Thermomix: Add flour and baking powder and mix for 20 seconds, Speed 5.
Roll the mixture into small balls (2 teaspoons of mixture per ball).
Place the cookie balls onto the baking trays and use the tip of your little finger to create an indent in the middle that goes approximately one-half of the way down). Fill the indent with Nutella.
Place the trays into the fridge and chill for 30 minutes (very important!!!)
Preheat oven to 170 degrees celsius (fan-forced). Grease and line two baking trays with baking paper.
Bake the cookies for approximately 10 minutes or until lightly golden.
Leave the cookies on the baking trays for 10 minutes and then transfer to a wire rack to cool completely.
Notes
RECIPE NOTES & TIPS
Soften your butter – Using room-temperature butter gives you a soft, creamy dough and ensures the cookies bake evenly.
Chilling the dough is essential - Don’t skip this step! It helps the butter solidify, which keeps the cookies from spreading too much in the oven.
Measuring the baking powder – Only a small amount is needed! Too much can cause the cookies to puff up and lose that classic thumbprint shape.
Make a good dent – Press firmly (but gently) to create a deep enough thumbprint – this helps hold plenty of filling without it spilling over.
Even spacing – Leave space between each cookie on the tray, as they will spread slightly while baking.
Nutella after baking? – If you prefer an extra gooey centre, you can add the Nutella once the cookies have cooled slightly.
Storage – Keep cookies in an airtight container at room temperature for up to 5 days.
Freezer-friendly – Freeze unfilled, baked cookies in an airtight container for up to 3 months. Simply thaw at room temperature, then add the Nutella before serving.