Line a 10×15-inch jelly roll or half-sheet pan with parchment paper and set it aside.

Using a hand mixer, beat together melted butter, peanut butter, granulated sugar, and vanilla extract until smooth and creamy. Beat in powdered sugar.Press the peanut butter mixture into a sheet pan, spreading to about ½-inch thickness.Place sheet pan in the freezer until firm (about 10 minutes or so).

Lift the parchment paper to remove the chilled peanut butter layer from the pan. Place a new sheet of parchment paper on the pan.Use a cookie cutter to cut out ½” thick Christmas tree shapes from the chilled peanut butter layer.

Place cutouts on a parchment-lined sheet pan. Freeze for 30 minutes.  Scoop up the left-over peanut butter mixture, repress to ½-inch thickness, and cut out additional trees.

After the cutouts have chilled for 20-30 minutes, prepare the chocolate coating.

Combine chocolate chips and 2 tablespoons of shortening in a glass bowl. Heat and stir in 30-second increments in the microwave until the chocolate is melted.Using a fork, lift one peanut butter cutout at a time and coat it completely with the melted chocolate. Tap the excess chocolate off and place it back onto the cookie sheet.Allow the chocolate to harden.