In a cup, add vanilla syrup, unsweetened cold brew, and ice cubes. Stir well to ensure the flavors are well combined, and set the cup aside.
In a separate cup, combine the pistachio syrup, 2% milk, and heavy whipping cream. Using a handheld milk frother, froth the mixture for 15-30 seconds until the mixture is thick and creamy, then pour over the top of your cold brew mixture.
Top with store-bought or homemade Brown Butter Topping (recipe below), and enjoy!