Line 8x8 inch pan with parchment paper.
In a mixing bowl, stir together peanut butter, melted butter, brown sugar, vanilla and salt, until sugar is dissolved.
Press the mixture into the prepared pan. Press it to flatten into about 1/2 inch thick layer.
Place in freezer until firm enough for cutting.
Line a tray with parchment paper, and with a tree cookie cutter, cut out the trees and place them in the freezer for 45-60 minutes until completely firm.
Melt the chocolate, and using a fork, cover each tree completely. Since the peanut butter trees soften fast, it is recommended to take a few trees from the freezer at a time.
Place chocolate covered trees on the parchment lined tray and refrigerate until chocolate has set.