Preheat oven to 350 degrees F. Line a 9 x 13-inch pan with aluminum foil and spray the bottom and sides with cooking spray and set aside.
In a large bowl with a hand mixer or in a stand mixer fitted with a paddle attachment, cream together the butter, sugars, egg, and vanilla.
In a separate bowl, combine the flour, baking soda, and salt, then add the flour mix to the wet ingredients in two separate additions, mixing until combined after each addition.
Mix in 1 cup of the mini chocolate chips.
Transfer the cookie dough to the prepared baking pan and use your hands to press and spread the dough out evenly to cover the entire pan.
Sprinkle the remaining 1/4 cup of mini chocolate chips over the dough and gently press into the dough using the palms of your hands.
Bake for 18 to 22 minutes until edges are golden brown.
Remove from oven and gently lift the cookie out of the pan by using the aluminum foil, transfer to a solid, flat surface.
Use a pizza cutter to cut 18 strips along the 13-inch side and then run the cutter once up the middle of the 9-inch side to create 36 cookie sticks.