In a medium-sized mixing bowl, combine all-purpose flour, granulated sugar, and salt. Drizzle in the melted unsalted butter and mix until the mixture resembles coarse crumbs. Transfer this crumbly dough into a greased 9x13-inch baking pan, pressing it evenly across the bottom to form a solid crust. Bake in a preheated oven at 350°F (175°C) for about 10-12 minutes, or until lightly golden.

While the crust cools, beat soft cream cheese in a separate bowl until it becomes smooth and creamy. Gradually add powdered sugar, mixing until fluffy. Next, whisk in eggs, vanilla extract, and heavy cream until the custard is silky and well combined.

Pour the custard mixture over the pre-baked crust, ensuring an even layer. Bake in the preheated oven at 350°F (175°C) for 25-30 minutes, or until the custard is set and slightly golden on top.

To create the rich chocolate glaze, combine dark chocolate chips and unsalted butter in a microwave-safe bowl. Heat in short bursts of 20-30 seconds, stirring in between until melted and smooth.

Once the chilled custard layer has firmed up, carefully drizzle or spread the warm chocolate glaze over the top. Let the glaze set at room temperature for about 30 minutes before slicing.

To serve, use a sharp knife warmed under hot water for clean cuts and slice the bars into squares.