Place the Greek yogurt in a fine-mesh sieve lined with cheesecloth and allow to drain for 30 minutes if the yogurt is not already thick (strained variety).
In a medium mixing bowl, combine the strained Greek yogurt and creamy peanut butter.
Utilize a hand mixer or stand mixer fitted with the whisk attachment to beat the mixture on medium speed until smooth and homogeneous.
Add the sifted powdered sugar, vanilla extract, and salt to the bowl.
Beat on low speed until the powdered sugar is incorporated to prevent dusting, then increase to medium-high and whip for 1-2 minutes until light and fluffy.
Apply immediately to cooled baked goods or store in an airtight container in the refrigerator for up to 3 days.