Preheat the oven to 350°F. Line a 13x18 sheet pan with parchment paper, spraying the parchment with non-stick cooking spray. Set aside. (Can also put in a 9x13 pan for extra thick cookie bars. Add 5-15 minutes to baking time.)
In another large bowl, using an electric mixer at medium speed, beat together the butter, and sugars about 2 minutes and is smooth.
Add the eggs and vanilla and mix on low speed until mixed in.
Sift the flour, baking soda and salt over the wet mixture and mix together until just incorporated. Do not keep mixing - do not overmix.
Add bag of chocolate chips in and stir with a wooden spoon, again no overmixing, just until incorporated. Dough will be very thick.
Spread thick cookie dough out evenly by dropping spoonfuls onto the baking sheet and spread out with fingers or it helps to spray a rubber spatula with non-stick spray.
Dough will spread out while baking, so you don't have to get the corners and edges perfect and will appear like you don't have enough, but you will.
Sprinkle mini chips to the top of the dough. (You can also have thicker bars with the recipe in the notes. It is not double the recipe, but 1 1/2 times the recipe)
Bake bars for 20 to 25 minutes or until golden brown. Cool in pan on wire rack. Makes 3-4 dozen bars depending how big you make them.