Preheat the oven to 425°F with a rack in the center. Lightly grease two 6-ounce ramekins. , In a large microwave-safe bowl, combine the white chocolate and butter. Microwave in 30-second increments, stirring between each, until the chocolate has completely melted. , Add in the ube halaya, confectioners’ sugar, ube extract, egg, and egg yolk; whisk until shiny and homogeneous. Stir in the flour and salt, mixing until no visible streaks of flour remain. , Divide the batter evenly between the prepared ramekins (about ¾ cup or 200g each) and place the ramekins on a baking sheet. , Bake the ube lava cakes for 18 to 20 minutes, or until the internal temperature reaches 165°F to 175°F on a digital thermometer. The sides of the cakes should be solid, but the centers should remain soft if the ramekins are jiggled slightly. , Let the ramekins cool on the baking sheet for 5 minutes. Cover each lava cake with a small serving plate and turn over to release the cake onto the plate. , Dust with confectioners’ sugar and top each ube lava cake with 1 tablespoon of macapuno strings. Garnish each with a dollop of whipped cream and a maraschino cherry. Serve while still warm.
