Preheat the oven to 350ºF.
In the bowl of a stand mixer, cream together the butter, peanut butter, and granulated sugar until light and fluffy. Add the coconut oil and continue mixing until fully combined, about 3 minutes.
Sift together the dry ingredients (flour, baking soda, and salt) and mix on low until a dough forms. Transfer to a lightly-floured surface and knead the dough until smooth and fully combined.
Using a rolling pin, roll out the dough to 1/8" thick. Use a cookie cutter of your choice (I used a plain circle cutter!) to cut out shapes, then lay them on a parchment-lined baking sheet.
Bake the cookies for 13-15 minutes until dry and crispy.