Preheat the oven to 350 degrees F. Line 2 baking sheets with parchment paper.
In a medium bowl, whisk together the flour, oats, baking soda, cinnamon and salt. In a separate large bowl using an electric mixer, cream together the brown sugar and butter, mixing until light and fluffy, about 3 minutes. In a blender or food processor, pulse the raisins, vanilla extract and eggs until no large chunks remain. Fold the raisin mixture into the creamed butter and sugar until fully combined. Slowly mix the dry ingredients into the wet ingredients and mix well.
Scoop 2 tablespoons of dough per cookie and portion on the prepared baking sheets, spacing them 2 inches apart. Bake in batches if necessary. Bake just until the edges start to brown, 12 to 14 minutes (don't overbake; the cookies may look slightly underdone when removing from the oven). Let the cookies cool on the baking sheets for 5 minutes before transferring to a wire rack to fully cool.
The cookies will keep in an airtight container for up to 3 days.