Preheat oven to 250ºF and line a baking sheet with parchment paper. Scatter white chocolate evenly over baking sheet and place in the oven for 5 minutes. Remove, and smooth out with a spatula. Place the white chocolate into the oven in 10 minute intervals, stirring/scraping up, and re-spreading the white chocolate each time. After 5-6* intervals (55-65 minutes total baking time), you should end up with a nice deep beige/butterscotchy color. Transfer caramelized white chocolate to a bowl.

Heat the heavy cream and milk in a saucepan on the stove until it just begins to simmer. Add the salt, vanilla, and caramelized white chocolate, whisking until completely smooth. If you still see bits of caramelized white chocolate, turn the stove on to low and continue stirring until hot chocolate is smooth.

Pour hot chocolate into mugs, top with whipped cream and caramelized white chocolate curls, if desired. Serve immediately.