In a stand mixer with the paddle attachment, cream butter, sugars and corn syrup on medium high for 2-3 minutes until fluffy and pale yellow in color. Scrape down the sides of the mixing bowl with a spatula.
On a lower speed, add eggs and vanilla to incorporate. Increase mixing speed to medium-high and start a timer for 10 minutes.
When time is up, on a lower speed, add the flour, baking powder, baking soda, and salt. Mix 45-60 sec just until your dough comes together and all remnants of dry ingredients have incorporated. Do not walk away from your mixer during this time or you will risk over mixing the dough. Scrape down the sides of the mixing bowl with a spatula.
On same low speed, add in your favorite baking ingredients and mix for 30-45 sec until they evenly mix into the dough. Add in your favorite snack foods last, paddling again on low speed until they are just incorporated.
Using a 6 oz. ice cream scoop, portion cookie dough onto a parchment lined sheet pan. Wrap scooped cookie dough tightly with plastic wrap and refrigerate for a minimum of 1 hour or up to 1 week. DO NOT BAKE your cookies from room temperature or they will not hold their shape.
Preheat oven to 400 degrees OR 350 degrees for a convection oven. Arrange your chilled cookie dough balls on a parchment sheet pan a minimum of 4-inches apart in any direction.
Bake 9-11 min. While in the oven, the cookies will puff, crackle and spread. At 9 minutes the cookies should be browned on the edges and just beginning to brown towards the center. Leave the cookies in the oven for the additional minutes if these colors don't match up and your cookies stills seem pale and doughy on the surface.
Cool the cookies completely on the sheet pan before transferring to a plate or an airtight container or tin for storage. At room temp, cookies will keep fresh 5 days. In the freezer, cookies will keep fresh 1 month.
Cook's Note: If the cookies spread too much after baking, take a knife OR the back of a spoon, and gently reshape them as soon as they come out of the oven.