Preheat the oven to 350 degrees. Line a baking sheet with parchment paper.
Cream together the butter and sugar with a hand mixer for 1-2 minutes.
Add in the egg and vanilla then beat until well combined and creamy. Make sure to scrape down the sides of the bowl.
Add the peanut butter and beat until creamy.
Mix the flour, baking soda and salt in a small bowl until well combined then gradually add to the creamy mixture until just combined; fold in the oats.
Using a tablespoon sized cookie scoop place 12 rounded spoonfuls onto the prepared baking sheet.
Place into the oven and bake for 12-13 minutes and then remove from the oven.
Rest on the baking sheet for a few more minutes before transferring them to a cooling rack to finish cooling. Repeat the process with the remaining dough.
While the cookies are cooling completely, melt the chocolate melting wafers with the coconut oil in the microwave for 30 seconds.
Remove and stir. Place back into the microwave and cook for another 10-20 seconds; remove & stir; repeat until melted.
Pour melted chocolate into a zip lock bag. Snip a very small corner off with scissors.
Place the cookies on the parchment paper and drizzle with melted chocolate.
Store the cookies in an air tight container layered between parchment paper.