01 - Preheat oven to 350°F. Line two baking sheets with parchment paper.
02 - In a medium bowl, whisk together flour, baking soda, salt, cinnamon, and nutmeg until evenly incorporated.
03 - In a large bowl, beat softened butter, brown sugar, and granulated sugar until light and creamy, approximately 2 to 3 minutes.
04 - Incorporate eggs one at a time, beating well after each addition, then mix in vanilla extract thoroughly.
05 - Gradually fold dry mixture into wet ingredients just until combined to avoid overmixing.
06 - Using a spatula, fold in rolled oats and raisins until evenly distributed throughout the dough.
07 - Drop heaping tablespoons of dough onto prepared baking sheets, spacing each about 2 inches apart.
08 - Bake for 10 to 12 minutes, or until edges are golden and centers appear just set.
09 - Allow cookies to cool on baking sheets for 5 minutes before transferring to wire racks to cool completely.