In a mixing bowl, combine the creamy peanut butter, powdered sugar, vanilla extract, and salt. Mix until smooth and well-blended.
Divide the peanut butter mixture into four equal parts, using your hands, shape each portion into tree forms (triangular shapes).
Place the shaped peanut butter trees onto a parchment-lined baking sheet and refrigerate for 30 minutes to firm up.
While the trees are chilling, melt the semi-sweet chocolate chips in a microwave-safe bowl, heating in 20-second intervals until fully melted and smooth.
If desired, add a few drops of green food coloring to the melted chocolate, mixing until the desired shade of green is achieved.
Remove the peanut butter trees from the refrigerator. Dip each tree into the melted chocolate, ensuring they are fully coated. Allow excess chocolate to drip off.
Before the chocolate sets, decorate each tree with mini chocolate chips and sprinkles as ornaments.
Once all trees are dipped and decorated, return them to the refrigerator for another 15-20 minutes to let the chocolate firm up.
Notes
Use different colors of sprinkles for a festive look.