Melt PB and Butter together in a glass bowl ( can do in microwave in 30 second intervals) and stir until smooth. Set aside to cool slightly
In another bowl whisk together the flour, baking powder, soda and salt.
In a large mixing bowl or bowl of stand mixer, cream together the sugar and eggs. Add in the melted peanut butter mixture and the vanilla extract. Mix until creamy, 3-4 minutes.
Add in the flour mixture and stir until combined. Add in the oats and mix again then gently add in the chocolate chips
Chill the dough for 2 hours up to overnight.
When ready to bake heat oven to 350 deg F. Set out cookie sheets with parchment paper or silicon bake mats.
Scoop out two tablespoon sized dough balls, can be a little bigger, then place on prepared bake sheets about two inches apart. Flatten slightly with hand. Bake for 12 minutes. Do not over bake.
Let cool for a few minutes on baking sheet then transfer to wire cooling rack to cool completely. Store in an airtight container or baggie. Can also freeze up to 3 months.