Step 1

Combine the instant espresso/coffee with the whole milk and set aside. In the bowl of a stand mixer, cream the butter on med-high until light and fluffy (about 5 minutes), scraping down the bowl and paddle a few times in between.

Step 2

Add the powdered sugar a few cups at a time, scraping down the bowl and paddle between intervals. Then add the vanilla, the coffee/espresso milk mixture, and salt. Mix on low until fully incorporated, about one minute.