In a microwave-safe bowl, combine white chocolate chips and butter. Heat in the microwave for 20-second intervals, stirring until melted and smooth, about 1 to 2 minutes.

In a separate bowl, beat softened cream cheese until creamy. Gradually add sweetened condensed milk, mixing until smooth.

Pour the melted chocolate into the cream cheese mixture and stir to combine. Add vanilla extract and powdered sugar, mixing until smooth.

Line an 8x8-inch baking pan with parchment paper, letting edges hang over. Sprinkle graham cracker crumbs across the bottom.

Spread the fudge mixture over the crust, smoothing the top and tapping the pan to release air bubbles.

Cover with plastic wrap or foil and refrigerate for at least 3 hours, ideally overnight, until set.

Once set, lift out of the pan using parchment edges, slice into squares, and serve chilled.