01 -
Grab a medium bowl and stir together plain flour, cornstarch, baking powder, and salt. Put it aside for now.
02 -
In a stand mixer with paddle or using hand mixer in a big bowl, mix the soft butter, white sugar, and brown sugar at medium-high speed until smooth and fluffy.
03 -
Drop in the ube jam and flavoring, then keep mixing until everything's well combined.
04 -
Add your egg and yolk, then beat until they're fully mixed in.
05 -
Add your flour mixture to the ube mix in three batches. Mix after each addition until you can't see any flour streaks, making sure to scrape the bowl edges.
06 -
Fold in your white chocolate chunks. Cover the dough with plastic and let it chill in the fridge for at least 3 hours.
07 -
Turn your oven on to 175°C (350°F) and put parchment paper on your baking tray.
08 -
Take about 2 tablespoons of dough and roll into balls. Place them on your tray about 2 inches from each other.
09 -
Stick them in the oven for 10-11 minutes or until they look set but not hard. Take them out and let them cool completely on the tray.
10 -
While they're still warm, push a few extra white chocolate chunks into the tops if you want. Just know this makes them a bit sweeter.