Preheat oven to 375°. Line cookie sheets with parchment paper.
Mix flour, baking powder and salt in a medium bowl with a spoon.
2 1/2 cups flour, 1/2 tsp baking powder, 1/4 tsp salt
In a large bowl, using a hand mixer, cream butter, sugars and vanilla together until well combined; add eggs and beat until combined. Add cooked oats and mix until combined.
1/2 cup butter, 1/2 cup sugar, 1/2 cup brown sugar, 1 tsp vanilla, 2 eggs, 1 cup cooked steel cut oats
Add flour mixture and stir, with a large spoon, until combined. Stir in chocolate chips.
1 cup chocolate chips
Drop by rounded tablespoons, or use a cookie scoop, onto prepared baking sheet and bake for 9-11 minutes, or until they look set and no indentation remains when touched.
Let cool on cookie sheet for about 5 minutes before moving to a cooling rack to cool the rest of the way.