Cream together the butter and brown & granulated sugar. Add eggs and vanilla and mix until fully combined and smooth.
In a separate bowl, sift together the flour, baking soda and salt. Add to the wet ingredients in two additions, mixing until homogenous and all dry flour is absorbed.
Add in oats 1/2 cup at a time, stirring well. This will take some elbow grease if stirring by hand!
Finally, add the carrots and chocolate chips (or other additions) and mix in until evenly distributed.
Cover the bowl and chill in refrigerator for at least 30 minutes.
When ready to bake, preheat the oven to 375F and line a baking sheet with parchment. Roll dough into balls 1 - 1.5 inches in diameter. Place on the baking sheet at least 2 inches apart. Bake in the center rack of the oven for 10-15 minutes (I found about 12 was perfect for my oven), until edges are lightly browned.
Carefully move to a cooling rack - wait a few minutes & then enjoy (I recommend with hot tea or cold milk)!