Place the sugar and butter in the bowl of a stand mixer. Use the whisk attachment on medium-high speed to mix together until the butter is pale and fluffy, about 3 to 4 minutes. Stop the mixer once halfway through mixing and scrape down the sides of the bowl.
While the butter and sugar are mixing, add the egg, milk, light corn syrup, and vanilla to a small bowl. Whisk everything together until smooth and the egg is well mixed in. Add the egg mixture to the butter and continue to whisk on medium-high until well combined.
Sift the flour into the mixing bowl, then add the baking powder, salt, and mini chocolate chips.
Switch to the paddle attachment and mix on low until a soft dough forms and clears the sides and bottom of the bowl.
Dump the cookie dough out onto a work surface and divide it roughly into two. Use your hands to roll each portion of dough into a log-shape about 2 inches (5 cm) in diameter. Wrap each cookie dough log in plastic wrap and store in the refrigerator for up to one week, or in the freezer for up to one month.
To Bake The Cookies
Preheat the oven to 350ºF (180ºC) and line a baking sheet with parchment paper.
Remove a cookie dough log from the fridge or freezer. Use a sharp knife to carefully slice the log into ¼ inch wide slices. Place the cookie dough slices on the prepared baking sheet leaving a bit of space around them.
Place the cookies in the preheated oven and bake for 10 to 12 minutes, or until the edges are lightly golden. Use a small offset spatula or a regular spatula to immediately transfer the cookies from the baking sheet to a wire rack to cool.
If you don't have or want to use light corn syrup you can omit it completely, however, this will change the final texture of the cookies.
If you don't own a stand mixer you can use a hand mixer or even make the cookies by hand. Just be sure to mix the butter until it is pale in color and fluffy, and stir the flour and chocolate chips in by hand with a wooden spoon or rubber spatula.