In a small pot, combine 1/4 cup of the milk, white chocolate, and sugar and heat over medium heat, stirring frequently, until chocolate and sugar are completely melted.
Remove pot from heat and add in remaining 1/2 cup of milk, cold coffee, and optional heavy cream.
Pour over ice, top with whipped cream if desired, and enjoy.
Notes
For a White Chocolate Mocha Frappuccino, double the sugar, and blend with ice until frosty.If you don’t have cold coffee, put a cup of hot coffee in the freezer for 10 to 20 minutes until it cools down to room temperature or brew a pot at double strength, pour 1 cup of coffee over 1 heaping cup of ice, and let it melt.