In a medium nonstick saucepan or skillet over medium heat, cook ube halaya with condensed milk until thickened and jammy, 6-8 minutes. Add powdered milk, lime zest, salt and sugar. Continue ...

Prepare the wet ingredients: In the bowl of a stand mixer (or using a hand mixer), beat the room temperature unsalted butter, brown sugar, egg, ube halaya jam, and ube extract on medium speed ...