Preparing the Crust
Preheat oven to 350F (175C). Grease and flour a 9x13 inch baking pan.
In a medium bowl, combine flour, softened butter, brown sugar, and salt.
Mix with a pastry blender or fingers until the mixture resembles coarse crumbs.
Press the mixture evenly into the prepared baking pan.
Bake for 15 minutes, or until lightly golden.
Making the Ube Filling
While the crust is baking, prepare the ube filling. In a large bowl, combine sweetened condensed milk, shredded coconut, white chocolate chips, ube halaya, ube extract, and flour.
Mix well until all ingredients are fully incorporated.
Pour the ube filling evenly over the pre-baked crust.
Baking the Bars
Return the pan to the oven and bake for 20 minutes, or until the filling is set and lightly golden.
Remove from oven and let cool completely in the pan before cutting into bars.
Optional Tips: For a richer flavor, brown the butter before making the crust. Substitute macapuno strings for shredded coconut if available. For a deeper purple color, add a few drops of purple food coloring to the filling. Ensure bars are completely cool to prevent breakage during cutting.