In a large bowl, using an electric hand mixer, beat together the butter, shortening, both sugars, vanilla, salt and cider vinegar. Beat until creamy and combined.
Beat in the egg, baking soda and flour until just combined. Stir in the chocolate chips. Divide the dough into two equal portions. Set aside.
For cream cheese filling: In a medium bowl, beat the cream cheese and sugar until creamy and combined. Then beat in the egg and vanilla.
In a 9×13 glass baking pan, press 1/2 of the chocolate chip dough evenly into the bottom of the pan. (You’ll need to use your clean hands to do this) Then spread the cream cheese filling over the top of the cookie dough in the pan. With the remaining cookie dough, flatten chunks of the dough in between your hands to form small disks. Place them all over the top of the cream cheese mixture. (Try to place them as close as possible, but they don’t have to touch)
Bake at 350 degrees F. for 28-30 minutes, or until the top is golden brown and cooked through.
*All ovens heat differently, some bars may take longer to bake. My oven seems to cook/bake things fast, so my bars were done at 27 minutes exactly*
Cool bars completely before serving. Store any leftovers covered in the fridge.