Cream softened butter and the sugars together in a large mixing bowl until well combined and smooth. Add the beaten eggs and vanilla, then stir to combine.
Add 2 1/2 cups flour, baking soda, baking powder and salt. Mix well to incorporate the dry ingredients, then do a roll test: roll the cookie dough into a ball between your palms-if the dough is sticky, add another 1/4 cup of flour, or just enough so that you can roll the cookie dough into a ball without it sticking to your palm.
Fold the chocolate chips and nuts (optional) into the cookie dough, then shape the dough into balls the size of walnuts and place them on greased cookie sheets. (6- 12 per sheet depending on the size. Note* the cookies tend to spread out in the oven so I like to leave an inch or two between the cookies.)
Bake in the preheated oven for 10-15 minutes until the cookies are golden, then remove them from the oven and allow the chocolate chip cookies to set on the cookie sheets for a few minutes before removing.
Notes
These cookies can be kept in an airtight container for up to a week or frozen for up to 30 days.Depending on the fat content of your butter you may need to add 2 3/4 cups flour. I generally add between 2 1/2-2 3/4 cups of all purpose flour, or just enough to be able to roll the cookies without them sticking to my palms. More notes below.