Preheat oven to 350°.
Whisk dry ingredients (flour, baking soda,
baking powder, salt); set aside.
Combine wet ingredients (butter, sugar, brown
sugar, eggs, vanilla) with a hand mixer on low.
To cream, increase speed to high and beat until
fluffy and the color lightens.
Stir the flour mixture into the creamed mixture
until no flour is visible.
(Over mixing develops the gluten, making a
tough cookie.) Now add the oats and raisins;
stir to incorporate.
Drop 2-inches apart onto baking sheet sprayed
with nonstick spray.
Bake 11-13 minutes (on center rack), until
golden, but still moist beneath cracks on top.
Remove from oven; let cookies sit on baking
sheet for 2 minutes before transferring to a
wire rack to cool.