Union Square Cafe Oatmeal and Chocolate Chip Cookies

1 stick butter, soft
1/2 c sugar
1/2 c dark brown sugar
1 large egg
1/2 tsp vanilla extract
1 c AP flour
1 1/4c cups rolled oats
1/4 tsp salt
1/2 tsp baking powder
1/2 tsp baking soda
6 oz semisweet chocolate (I've made it with more, or milk, or whatever - it works)

Directions

Preheat oven to 400F. Butter or parchment (or preferably silpat) two cookie sheets.Cream butter and both sugars together until "smooth and fluffy". Add egg and vanilla and blend thoroughly (I add the vanilla to the egg first). Add everything else to the bowl except the chocolate. Mix on low to incorporate. Fold in the chocolate by hand with a rubber spatula. 12 cookies per sheet, 2tbsp each, flatten. Bake each sheet separately for 9 minutes "until the cookies have spread and puffed slightly, but have not browned". Cool for 10 mins, then put on a rack.