Preheat your oven to 350°F (175°C). Line a baking sheet with parchment paper.
In a medium bowl, whisk together the flour, baking soda, and salt. Set aside.
In a large bowl, mix together the melted butter, brown sugar, granulated sugar, and vanilla extract until well combined.
Add the ube halaya to the wet ingredients and mix well.
Gradually add the dry ingredients to the wet ingredients, mixing just until combined.
Fold in the rolled oats.
Scoop tablespoon-sized portions of dough onto the prepared baking sheet. Press down gently to flatten each cookie.
Bake for 10-12 minutes, or until the edges are golden brown.
Allow the cookies to cool on the baking sheet for 5 minutes, then transfer to a wire rack to cool completely.
