Line the inside of a cookie sheet with parchment paper and make sure there is a spot in your freezer where it can lay flat. Melt about 2/3 of the chocolate coating according to the package directions. (It is usually easiest in the microwave.) Pour the melted chocolate into the center of the parchment paper and spread it out until it is approximately 1/8" thick. Place the cookie sheet in the freezer to harden while you prepare the filling.
In a large bowl or the bowl of a stand mixer, beat together the peanut butter, melted butter and vanilla extract until combined. Sift the powdered sugar into the bowl and mix until completely combined.
Remove first layer of hardened chocolate from the freezer and spread the peanut butter filling evenly to cover the entire surface of the chocolate. Return the pan to the freezer to harden for about 15 minutes.
When the filling has had a chance to harden in the freezer, melt the remaining chocolate coating. Remove the pan from the freezer and spread the chocolate evenly over the top of the peanut butter filing. (This layer will be slightly thinner than the bottom layer.)
Return the pan to the freezer until completely set. Break up the bark into pieces and serve or store in the refrigerator until ready to eat. Enjoy!
Notes
We use Peter Pan peanut butter because it is extra creamy and makes for a really nice texture!