Preheat the oven to 350 degrees F (177 degrees C).
Prep 2 baking sheets by covering them with parchment paper.
Combine 1 ⅔ cup of all purpose flour, ½ tsp of baking soda, ½ tsp of baking powder, and ¼ tsp of salt in a small bowl. Mix and set aside.
In a separate bowl or the bowl of a stand mixer, whisk together ½ cup of unsalted butter and 1 cup of granulated sugar until well combined.
Add 1 egg and 2 tsp of vanilla extract to the mixer. Mix until combined.
Combine the dry ingredients from step 1 with the wet ingredients. Mix until just combined.
Scoop out ⅔ of the dough into a separate bowl. Add ¾ tsp of ube extract and mix until the dough is completely purple.
Take 2 tbsp of dough from the ube dough and 1 tbsp from the vanilla dough, and combine them into 1 cookie dough ball. Each ball should be ~50 grams.
Add ½ cup of granulated sugar to a small bowl. Coat the dough ball in granulated sugar. Repeat this process until you run out of cookie dough.
Bake the cookies for 10-12 minutes until the edges are slightly brown.
Cool for 10 minutes on the baking sheet before transferring to a cooling rack to cool completely.