In a large bowl, combine 2 cups flour, 2 tsp baking powder and 1/2 tsp salt. Set aside.
Using a handheld electric mixer or a stand mixer fitted with the paddle attachment, combine 1/2 cup sugar, 7 oz ube jam (or ube halaya) and 1/2 cup oil until incorporated. It is important that you taste the mixture at this point (before you add eggs) so you can see if it needs more sugar. Like I mentioned, ube jams are different so you need to adjust according to taste.
Once you’re okay with the flavour, add 2 eggs (which you've already beaten) and 3 tsp ube extract. Stir until combined.
Add your flour mixture to your ube mixture in thirds and gently stir on low speed until combined.
Cover the bowl with your cookie dough with cling wrap and chill in the fridge for at least 4 hours.
When you’re ready, preheat your oven to 350F. Prep a baking sheet by lining it with parchment paper (or silicone baking mats). Set aside.
Scoop a heaping tablespoon of ube cookie dough and, using your hands, roll into a ball. Thoroughly coat each ball with confectioner's sugar before placing it on the cookie sheet. Make sure to space your cookies about 1-2 inches apart.
Bake in the preheated oven for 10-13 minutes or until they crack on top and start looking matte. They will be soft coming out of the oven but don’t worry, they will continue to set as they cool so do not over bake. Cool in the pan for a couple of minutes before transferring to a rack to cool completely.
It is easier to work with room temperature ube jam vs one straight out of the fridge so make sure to leave it out on the counter for at least 30 minutes before you plan to use it.
These cookies are going to look a tad under-baked but don't be tempted to continue baking them because they will turn rock hard. As soon as they crackle, turn matte and start to firm up, you can bring them out of the oven. They will continue to set while on the hot pan.