Preheat oven to 350 degrees F (177 degrees C).
Grease a 8×8 baking pan with butter and line with parchment paper. Set aside.
Melt the butter. Set aside to cool.
Mix all purpose flour, baking powder, and salt together in a bowl. Set aside.
In a separate bowl, combine melted butter and brown sugar. Mix until just combined. Add the egg, vanilla extract, ube extract, and ube halaya. Whisk until combined.
Add your dry ingredients from step 4 to your wet ingredients. Mix until just combined.
Lastly, add in the white chocolate chips and mix.
Spoon batter into your prepared baking pan. Smooth it out with your spatula.
Bake for 25-30 minutes until a toothpick comes out clean.
Let blondies cool completely before cutting into them.