Preheat oven to 350°F. Line two baking sheets with parchment.
Whisk flour, baking soda, cinnamon, and salt in a medium bowl.
Cream butter, brown sugar, and granulated sugar until light and fluffy.
Beat in eggs one at a time, then mix in vanilla.
Add dry ingredients in two additions. Mix just until a soft dough forms.
Fold in oats, raisins, and pecans until evenly distributed.
Scoop heaping 2-tablespoon portions onto sheets, spacing about 2 inches apart.
Bake 10–12 minutes, until edges are set and centers look slightly soft.
Cool on the pan 5 minutes, then transfer to a rack to finish cooling.