Make the cookie topping (optional). In a small skillet, melt the butter over medium heat. Continue to heat until browned, then stir in the crushed cookies. Continue to cook for another 30 seconds, then remove from heat and set aside.
Make the latte. Whisk together the milk and pistachio syrup in a small saucepan and heat over medium heat until steaming and just starting to foam.
Remove from heat and frother slightly with a whisk or milk frother. Set aside.
Brew your coffee into a coffee mug. Top with the pistachio milk.
Top with whipped cream and/or 1 tablespoon of the brown butter cookie topping if desired. Drink up!
Notes
***Cookie Topping: The cookie topping portion of this recipe yields 4 tablespoon of the topping, enough for 4 drinks. Store leftover cookie topping in an airtight container for up to 7 days at room temperature.