Step#2: Put the flour, baking soda, and baking powder in a bowl and mix together with a fork or whisk to make sure it combines.
Step #3: Add the sugar, brown sugar (ADD A HEAPING 1/2 CUP BROWN SUGAR TO MAKE THEM GOOIER! Otherwise just add equal amounts of sugar and brown sugar), butter, shortening, egg, vanilla, and salt in to the bowl. If you want to, ad 1/2 tsp of butter flavoring. I think it's lovely.
DO NOT USE ELECTRIC MIXER! I swear those things have ruined baking. It's very easy to over-work dough of any kind. If you overwork the butter and shortening, your cookies will turn out flat. Keep it simple; one bowl and a big wooden spoon.
Step #4: Once all of this is combined, add in the chocolate chips and put dough in the fridge for 10 minutes. (You don't have to, but it will also help the cookies be less flat.
Step #5: Put 1/2 inch balls of dough on a cool, nonstick cookie sheet (I like using parchment paper). Don't put the dough on a warm cookie sheet: that will also flatten your cookie! You don’t need to roll them in to perfect balls, but I think they look prettier.
Step #6: Bake for 8-10 minutes at 375° or until light brown around the edge. Start at 7 minutes and check them because you never know how your oven compares to mine. :) Also I like mine a gooey-to-the-point-of-almost-raw.
Step #7: Let them cool (a little) and serve with milk!