01 - Preheat oven to 350°F. Line two baking sheets with parchment paper.
02 - Whisk together flour, cinnamon, ginger, nutmeg, baking soda, baking powder, and salt in a medium bowl.
03 - Beat softened butter, brown sugar, and granulated sugar in a large bowl until light and fluffy.
04 - Mix in egg and vanilla extract until fully incorporated.
05 - Stir in grated carrots until evenly distributed.
06 - Gradually add dry ingredients to wet mixture, mixing until just combined.
07 - Fold in oats, nuts, and raisins if using.
08 - Drop tablespoon-sized mounds of dough onto prepared baking sheets, spacing 2 inches apart.
09 - Bake for 11-13 minutes until edges are golden and centers are set. Cool on baking sheet for 5 minutes, then transfer to wire rack.
10 - Beat cream cheese and butter until smooth. Add powdered sugar, vanilla, and salt; beat until fluffy.
11 - Spread or pipe frosting onto completely cooled cookies.