Place the softened butter in a large mixing bowl and beat it with an electric mixer for about 2 to 3 minutes until smooth and creamy. Add the powdered sugar and granulated sugar gradually, then continue beating until the mixture becomes light and fluffy.

Creaming the butter properly helps create a delicate texture without making the cookies overly dense. Avoid using melted butter because it can make the dough too soft and affect the final shape of the cookies.

Add the vanilla extract and sweetened condensed milk to the creamed butter mixture. Beat briefly until everything is evenly incorporated.

If you’re making an ube version, add a small amount of ube extract at this stage. You can also add finely grated cheddar cheese or desiccated coconut for an extra Filipino-inspired flavor.

In a separate bowl, sift together the all-purpose flour, cornstarch, and salt. Sifting removes lumps and helps distribute the cornstarch evenly throughout the flour.

The cornstarch is especially helpful because it gives the shortbread a lighter, more delicate texture while reducing the amount of gluten that develops during mixing.

Gradually add the dry ingredients to the butter mixture, mixing on low speed until a soft dough begins to form. Switch to a rubber spatula if necessary and gently bring the dough together.

Avoid overmixing once the flour has been incorporated. Overworking the dough can develop too much gluten and result in cookies that are less tender.

Shape the dough into a flat disk, wrap it tightly in plastic wrap, and refrigerate for approximately 30 minutes. Chilling allows the butter to firm up, making the dough easier to roll and helping the cookies maintain their shape during baking.

While the dough chills, preheat your oven to 350°F (175°C) and line your baking sheets with parchment paper.

Remove the chilled dough from the refrigerator and place it on a lightly floured surface. Roll it out to about ¼-inch thickness using a rolling pin. Use a round or decorative cookie cutter to cut the dough into evenly sized cookies.

Transfer the cookies carefully to the prepared baking sheets, leaving a little space between each one. If the dough becomes too soft while working, refrigerate it for a few minutes before continuing.

Place the baking sheets in the preheated 350°F (175°C) oven and bake for approximately 12 to 15 minutes. The cookies should look set with lightly golden edges while the centers remain relatively pale.

Avoid overbaking the cookies because shortbread should have a delicate, tender texture rather than becoming dark and crunchy.

Remove the cookies from the oven and let them cool on the baking sheet for about 5 minutes. Carefully transfer them to a wire cooling rack and allow them to cool completely.

Once cooled, dust them lightly with powdered sugar if desired. You can also drizzle them with melted white chocolate or decorate them with a small amount of ube-flavored icing for a more festive Filipino-inspired finish.