1. Preheat oven to 350°F (175°C). Line or grease a baking sheet.
2. Whisk flour, oats, baking powder, cinnamon, nutmeg, cloves, and salt in a bowl.
3. Cream butter, brown sugar, and granulated sugar in a large bowl. Beat in egg and vanilla.
4. Gradually add dry ingredients to wet ingredients, mix until combined. Stir in carrots, nuts (optional), and raisins (optional).
5. Drop spoonfuls of dough onto prepared baking sheet, spacing 2 inches apart. Flatten slightly.
6. Bake for 10-12 minutes until lightly golden. Cool on sheet, then transfer to wire rack.
7. Prepare frosting: beat cream cheese, butter, powdered sugar, and vanilla until smooth.
8. Spread frosting on cooled cookies. Optional: sprinkle with nuts or cinnamon.
9. Store leftovers in the refrigerator. Enjoy!