Preheat oven to 350 degrees F. In a mixing bowl, stir together flour, oats, baking soda, cinnamon, and salt. In a stand mixer or in a bowl using a hand held beater, beat softened butter, brown sugar and white sugar/ Beat until light and fluffy - about 2 minutes. Add in the eggs and vanilla until incorporated. Slowly add in the flour mixture and stir just until incorporated. Lastly fold in the carrots and any other optional ingredients (nuts, raisins).