Heat the butter in a light-colored pan over medium heat. Stir frequently until it melts, foams, and the solids start to turn golden.
Remove from heat and set aside half to stir into the espresso.
Stir brown sugar into the other half to make the topping and set aside.
Prepare the espresso
Prepare the espresso using an espresso machine, a French press, or instant espresso. You can also use strong brewed coffee. Add half of the browned butter.
Steam and froth the milk
Heat the milk to about 150 F. (It will start to steam and feel warm to the touch.) Add the pistachio syrup, and froth with a handheld milk frother. (If you don’t have a frother, you can use an immersion blender or put the milk in a jar and shake until foamy.)
Pour on top of the espresso.
Sprinkle on the topping
Top the pistachio latte with the salted brown butter topping and enjoy!
Notes
Iced Pistachio Latte
To make an iced Pistachio Latte, use cold milk instead of steamed and pour over a glass of ice. I leave the brown butter out when iced because it hardens in the icy drink.