In a large bowl using an electric mixer, cream the butter and peanut butter on medium speed until combined.
Mix in te sugar, egg and vanilla.
Add in the flour, baking soda and salt and mix on low speed until combined.
Turn off the mixer and fold in the chocolate chips with a spatula.
Cover and chill in the refrigerator for at least 2 hours, up to 2 days.
When ready to bake, preheat the oven to 350F. Form dough into balls in 1-2 tablespoon size. Place 2 inches apart on a stone baking sheet or regular cookie sheet. Bake cookies for 8-10 minutes depending on desired crispiness. The tops may not be completely set.
Let cool for 5 minutes on baking sheet then transfer to a cooling rack to let cool completely.
Cookie dough can be placed in a ziplock bag and frozen for later use.
I use crisco baking butter instead of regular butter in cookies, however you can use room temperature butter in place of crisco butter.