Prepare the Crust: In a medium bowl, combine graham cracker crumbs, sugar, and melted butter. Press mixture firmly into the bottom of a 9-inch springform pan.
Chill the Crust: Place the prepared crust in the refrigerator while preparing the filling. A chilling time of at least 30 minutes is recommended.
Bloom the Gelatin: In a small bowl, sprinkle gelatin powder over cold water. Let stand for 5-10 minutes to soften.
Prepare the Filling: In a large bowl, beat softened cream cheese until smooth. Gradually add sweetened condensed milk and mix until well combined.
Incorporate Ube: Stir in ube halaya and ube extract until evenly distributed, ensuring no lumps remain.
Dissolve Gelatin: Heat the bloomed gelatin in the microwave for 15-20 seconds, or until completely dissolved. Stir to ensure no granules remain.
Temper the Gelatin: Gradually drizzle the dissolved gelatin into the cream cheese mixture while mixing on low speed. This prevents the gelatin from setting too quickly.
Whip the Cream: In a separate bowl, whip heavy cream until stiff peaks form.
Combine Mixtures: Gently fold whipped cream into the cream cheese mixture until fully incorporated. Avoid overmixing.
Pour and Chill: Pour the filling over the chilled crust, spreading evenly. Cover the springform pan with plastic wrap and refrigerate for at least 6 hours, or preferably overnight, to allow the cheesecake to set completely.
Serve: Before serving, carefully remove the cheesecake from the springform pan. Garnish as desired with whipped cream, ube halaya, or grated ube.
Optional Tips: For a richer crust, substitute digestive biscuits for graham crackers. If ube halaya is unavailable, increase the amount of ube extract to taste, adding a small amount of purple food coloring for visual appeal. Adjust sweetness by reducing the amount of sweetened condensed milk. For a vegan version, substitute cream cheese and gelatin with plant-based alternatives, adjusting setting times accordingly.