Start by softening the unsalted butter to room temperature. Measure out your sugars, flour, baking powder, baking soda, salt, and sift the dry ingredients together in one bowl. In another bowl, beat the eggs, then mix in the ube halaya and vanilla extract until smooth.
Using an electric mixer, cream the softened butter with granulated sugar and brown sugar until the mixture is light and fluffy, about 3-5 minutes on medium speed.
Gradually add the ube mixture to the creamed butter and sugar, beating well to combine. Then, slowly incorporate the dry ingredients until a soft dough forms. Be careful not to overmix.
Wrap the dough in plastic wrap and refrigerate for at least 1 hour to firm up the dough.
Once chilled, scoop out tablespoon-sized portions of dough and roll them into balls. Roll each ball generously in powdered sugar to coat completely.
Place the coated dough balls onto a parchment-lined baking sheet, spacing about 2 inches apart. Bake in a preheated oven at 350°F (175°C) for 10-12 minutes until edges are set and centers are soft and fudgy.
Allow the cookies to cool on the baking sheet for 5 minutes before transferring to a wire rack to cool completely. Enjoy!