In a large bowl, using a mixer at medium speed, beat together the butter, and sugars until mixed together well and smooth.
Add the eggs and continue mixing until mixed together well.
Gradually add the flour, salt and baking soda and mix in until just incorporated. Do not overmix.
Add chocolate chips and fold in with a wooden spoon or spatula.
Place a little over half of the dough into the 9 x 13 pan and use your fingertips to spread it out to the corners of the pan and level.
With the remaining cookie dough, use a small ice cream scoop or heaping tablespoon and drop the dough onto the prepared baking sheets, you should get 8 medium sized cookies and flatten with down the cookies just a bit with hands or bottom of a cup slightly so they bake more evenly.
Place the 9x13 pan of cookie layer in the oven and bake for 15-17 minutes.
Place the cookies in the oven at the same time and take out after 10 minutes.
Let the cookies cool for 5 minutes on the baking sheets, then transfer the cookies to wire racks to cool completely. After cooled, break up the cookies for the top layer.
After the cookie layer has baked, let it cool completely before adding the creamy layers.