Preheat the oven to 375.
Optional: if you want toasted pecans for a richer flavor, pour the pecans in a skillet and saute them over medium heat for 5-7 minutes. This will help release some of the oils and the flavors. The recipe will be delicious without toasting them, but they'll be a little more flavorful if you do! :)
Cream butter & sugars together on medium speed for about 2 minutes.
While the butter & sugars are creaming together, pour 3 c flour (leave that other 2 tbsp for later!), baking soda, and salt in a separate bowl and gently mix together with a whisk, and then set aside.
Add in vanilla & egg to the creamed butter and sugar until egg is combined, scraping the bowl to make sure everything evenly mixes together.
Slowly add in the flour mixture to the creamed butter, and mix together until just combined.
Gently mix in the chocolate chips & pecans.
Now, for a silly-but-always-works trick for helping those cookies not to spread: sprinkle in the remaining 2 tbsp of flour into the cookie dough and quickly mix together - just a couple of rotations around the bowl! (You don't need to do this if you decide to make the dough ahead of time and chill it.)
Roll out your cookie dough - the dough balls should be about 1.5-2 inches in diameter. Once you've rolled out 12 and placed them on your baking pan, bake on the center rack in the 375 degree preheated oven for 9 minutes.
Remove the baked cookies from the oven, and allow them to sit on the baking pan for 5-10 minutes before placing them on a cooling rack.
Repeat with remaining dough.
Enjoy those cookies with your friends & fam!