Preheat the Oven:
Preheat your oven to 350°F (175°C). Line several baking sheets with parchment paper.
Cream the Butter and Sugars:
In a large bowl or stand mixer, cream together the softened butter, brown sugar, and granulated sugar until light and fluffy.
Add Eggs and Vanilla:
Add the eggs and vanilla extract, mixing until well combined.
Combine Dry Ingredients:
Add the flour, oats, baking soda, baking powder, cinnamon, and salt. Mix until combined.
Add Carrots, Coconut, and Raisins:
Stir in the grated carrots, unsweetened coconut, and raisins until evenly distributed.
Form the Cookies:
Drop the dough by tablespoonfuls, 2 inches apart, onto the prepared baking sheets. If desired, use damp hands to smooth the edges of the dough balls for a uniform shape.
Bake:
Bake for 9-10 minutes, until the edges are golden and the tops no longer appear shiny. Let the cookies cool on the baking sheet for 5 minutes before transferring them to a wire rack to cool completely.
Make the Frosting:
Once the cookies have cooled, beat the cream cheese, softened butter, and vanilla extract together until smooth. Gradually add the powdered sugar, whipping until the frosting is light and creamy.
Assemble the Cookies:
Use a tablespoon-sized scoop to place frosting on the flat side of one cookie. Top with another cookie (flat sides together) and gently press to spread the frosting evenly. Repeat with the remaining cookies.
Let the Frosting Set:
Allow the frosting to set for 1-2 hours before serving. Store the cookies between layers of wax paper in an airtight container in the fridge for 5-7 days.