Preheat the oven to 350°.
Line you baking sheet with parchment paper or a silicone baking mat. Set aside.
In the bowl of a stand mixer or with an electric hand mixer, cream together the peanut butter, margarine, butter, brown sugar and sugar until well combined.
Scrape the sides of the bowl and add in the egg. Mix until combined.
Add the flour, baking soda and salt, mix until the sticky dough forms.
Mix in the peanut butter chips.
Portion the dough out into approx 2 1/2 tbsp portions. I use two scoops from my #50 scoop for each cookie. Roll into a ball and place on the prepared baking sheet.
Repeat with the remaining dough. Flatten the cookie dough so it looks like a hockey puck.
Bake at 350° for 11-13 minutes. The cookie will spread just slightly and the edges should start to turn golden brown when they are ready to come out of the oven.
Allow the cookies to cool on the pan for 5 minutes before transferring to a wire cooling rack.
Store in an airtight container at room temperature for up to 3 days or in the freezer for up to 3 months.