Preheat oven to 350°F; line baking sheets with parchment.
Cream butter and both sugars in a large bowl about 3 minutes, until light and fluffy.
Beat in eggs one at a time; mix in vanilla.
Separately whisk flour, baking soda, and salt.
Gradually mix dry ingredients into wet just until combined.
Gently fold in oats, chocolate chips, and raisins evenly.
Drop rounded tablespoons onto prepared sheets, 2 inches apart.
Bake 10-12 minutes, until edges are golden and centers look slightly underdone.
Cool on sheet 5 minutes; transfer to wire rack to cool completely.