Preheat the oven to 350°.
In the bowl of a stand mixer or using an electric hand mixer, cream together the butter, peanut butter, brown sugar and granulated sugar. Mix until well combined.
Scrape the sides and add in the eggs, canola oil and vanilla extract. Mix to incorporate all of the ingredients.
Add in the flour, baking powder, baking soda and salt. Mix until the dough comes together.
Fold in 1 cup of the chopped peanut butter cups.
Scoop the dough out in heaping 1/3 cup portions, flatten each portion slightly so it is about 1 inch thick and then arrange on your pan. Place 6 cookies on to each pan.
Bake at 350° for 13-15 minutes. You'll know the cookies are done once they have expanded a bit, the cookies are just starting to crackle a little and the very edges of the cookie just barely start turning a golden brown.
Allow the cookies to cool on the pan for 15 minutes.
Melt the peanut butter chips in a microwave safe bowl. Microwave the peanut butter chips for 1 minute, stirring at the 30 second mark.
Portion out 1 1/2 tbsp of melted peanut butter chips onto each cookie and spread to cover the top of the cookie.
Immediately top with some of the leftover chopped peanut butter cups.