Preheat the oven to 350 degrees F (177 degrees C).
Prepare a 8x8 baking pan by greasing it and covering it with parchment paper.
Brown the butter. Heat butter over medium heat until it melts. Then lower the heat to low and cook until brown bits appear.
Put the white chocolate into a bowl. Pour the browned butter over the top. Stir until all the chocolate melts. Set aside.
Combine sugar, brown sugar, eggs, vanilla extract, ube extract, ube halaya jam, and salt in a large bowl or the bowl of a stand mixer. Using a hand mixer or stand mixer, whisk until it becomes a fluffy, light purple color (~5-10 minutes).
Add the white chocolate mixture to the wet ingredients. Mix until incorporated.
Add the all purpose flour and gently fold it into the mixture.
Pour the batter into the prepared baking pan.
Bake for 20 minutes.
Take out the brownies and tap on the counter to release air bubbles. Optional: Sprinkle flaky salt on top of the brownies.
Put them back in the oven and bake for another 15-20 minutes.
Let the brownies cool for 20 minutes in the pan before cutting into them.