Combine peanut butter, butter powdered sugar in a mixer fitted with a paddle attachment and mix on medium-high speed until creamy, about 5 minutes. Add honey and salt a little at a time, tasting as you go. Mix until well combined.
For the ganache, mix melted white chocolate and peanut butter filling until smooth.
To assemble
Put peanut butter filling in a pastry bag with a large round tip or large ziplock and cut a hole in one corner. Pipe filling on one side of the cookie and place the second on top. If the ganache is too thick, microwave for a few seconds. Use a fork or spoon to decorate.
Recipe by oh honey bakes at https://ohhoneybakes.com/dark-chocolate-peanut-butter-cookie-cows/