Soften the cream cheese: Let the cream cheese sit at room temperature for 30 minutes, then beat it with a hand mixer until smooth and lump-free, about 2 minutes.
Melt the white chocolate: Melt the white chocolate chips in the microwave in 20-second bursts, stirring between each, until smooth. Let it cool for a few minutes so it doesn't melt the whipped topping later.
Mix sugar and vanilla: Add the powdered sugar and vanilla extract to the cream cheese and beat on low speed until the mixture turns pale and even, scraping down the bowl once.
Add the melted chocolate: Pour in the cooled melted white chocolate and beat again until fully combined and glossy, about 1 minute.
Fold in whipped topping: Add the whipped topping and fold it in gently with a spatula, using broad strokes just until no white streaks remain. Overmixing will deflate the dip and make it dense.
Crumble the snack cakes: Crush the vanilla snack cakes into small crumbs with your hands or a fork, keeping the pieces slightly uneven for texture.
Fold in half the crumbs: Gently fold half of the crumbled snack cakes and half the sprinkles into the dip, swirling just enough to distribute the color and crumbs evenly.
Transfer to a serving bowl: Spoon the dip into a shallow serving bowl and smooth the top with the back of a spoon so it's level.
Top with remaining crumbs: Scatter the remaining crumbled cake and sprinkles over the top right before serving so they stay crunchy instead of softening.
Chill if needed: If you're not serving right away, cover the dip and refrigerate for up to 2 hours before adding the top layer of crumbs and sprinkles.
Serve with dippers: Set out graham crackers, vanilla wafers, or pretzel sticks alongside the dip and serve within an hour of adding the crunchy topping for the best texture.