Preheat oven to 375 degrees F.
Cream together butter, shortening, granulated sugar, light brown sugar, eggs, and vanilla.
Ass salt and baking soda, mix thoroughly.
Add flour, allowing mixture to incorporate fully.
Fold in milk chocolate chips until evenly distributed.
Drop a heaping tablespoon worth of dough for each cookie onto the baking sheet.
Bake for 8-10 minutes. These cookies should be very soft inside when you take them out, so watch them closely near the end of the baking time.
Allow to cool for 3-5 minutes then transfer to cooling rack. These cookies are delicious served warm but are even better the 2nd day when stored in a ziplock bag!