Step 1
In a medium bowl, whisk together. 1¼ cups (156 grams) all-purpose flour, 1 tbsp. Baking powderand ¼ teaspoon kosher salt.
Step 2
In a large bowl, using a hand mixer, beat. 1 stick (113 grams) unsalted butter, melted and completely cooled.and ⅔ cup (133 grams) granulated sugar Beat on medium-high speed until well combined, about 1 minute (note that the butter is melted so it will be looser than the creamed softened butter and sugar).
Step 3
add ½ cup (124 grams) Obe stir-fry, at room temperatureand 1 tbsp. (7 grams) mixed milk powder and beat until well combined, about 30 seconds. add 1 large egg, at room temperatureand 1 tbsp. ube paste and beat until well combined (it’s okay if it looks a little runny).
Step 4
Add the flour mixture together and beat on low speed until mostly combined but not quite. Finish mixing with a rubber spatula. Cover the bowl with plastic wrap and refrigerate for at least 3 hours and up to overnight.
Step 5
When you’re ready to bake, use 1½ tbsp. Scoop mounds of dough onto a parchment-lined sheet pan. Break each mound into a 2″ (5-cm) disk. If things stick, dust your hands with additional flour as needed (but don’t overdo it).
Step 6
Toss the discs in the extra sugar until coated and transfer to a dinner plate (this will take up less space in the fridge). Cool for 15 minutes.
Step 7
Meanwhile, preheat oven to 350°F (180°C).
Step 8
Add to a small heatproof bowl. 75 grams white chocolate, finely chopped (about ⅓ cup)and microwave in 15-second increments, stirring in between, until melted and smooth. Transfer 8 chilled dough disks to a parchment-lined sheet pan (alternating three rows of 2 with two rows of 1).
Step 9
Using a small offset spatula, spread a layer of melted white chocolate over the dough disks. Add a few random vertical swipes to the sides. Bake for 12 to 13 minutes, until the top is bubbly and the edges are firm.
Step 10
Transfer the pan to a wire rack and let cool for 5 minutes. Transfer the cookies to a wire rack and let cool completely.
Step 11
Repeat with the remaining dough, using a fresh parchment-lined sheet pan and thinning the white chocolate by microwaving it for another 15 seconds or so.