Nonstick cooking spray, for the pan
3 cups sugar
1 cup butter
1 cup heavy cream
2 teaspoons vanilla extract
Pinch salt
1 cup milk chocolate chips
1 cup white chocolate chips
One 7-ounce jar marshmallow cream, such as Fluff
1/4 cup malted milk powder, such as Ovaltine
1 cup malted milk balls, such as Whoppers, broken into pieces
1 pint vanilla ice cream, for serving