Melt the chocolate by combining white chocolate chips and butter in a microwave-safe bowl. Microwave in 20-second intervals, stirring until smooth. Set aside to cool.

In a separate bowl, beat softened cream cheese until smooth, then gradually mix in sweetened condensed milk until fully integrated.

Pour the cooled melted chocolate into the cream cheese mixture. Add vanilla extract and powdered sugar, and stir until well blended and smooth.

Line an 8x8 inch baking dish with parchment paper and sprinkle graham cracker crumbs across the bottom.

Pour the cheesecake fudge mixture over the crust and spread evenly. Tap the pan gently on the counter to remove air bubbles.

Cover with plastic wrap and refrigerate for at least 3 hours. For best flavor and texture, chill overnight.

Remove from the pan using parchment overhang and slice into squares for serving.