Preheat the oven to 350°F. In a large mixing bowl, use an electric mixer to cream the butter and sugar until light and fluffy. Add the eggs one at a time, mixing well after each addition.

Stir in the ube halaya and vanilla extract until the mixture is smooth and well integrated.

In a separate bowl, whisk together the flour, baking powder, and salt. Gradually fold the dry mixture into the wet ingredients using a spatula.

Pour the batter into a greased and floured 9-inch round cake pan. Smooth the top with a spatula.

Place the pan in the preheated oven and bake for about 50 minutes, or until a toothpick inserted into the center comes out clean.

Allow the brownies to cool in the pan for 10 minutes before transferring them to a wire rack to cool completely. Cut into slices and serve.

Store any leftover brownies in an airtight container at room temperature for up to 3 days.