01 - Preheat oven to 350°F. Line a baking sheet with parchment paper.
02 - In a medium bowl, whisk together flour, baking powder, baking soda, salt, cinnamon, ginger, and nutmeg until well blended.
03 - In a large bowl, beat butter, brown sugar, and granulated sugar together until creamy and well combined, about 2-3 minutes.
04 - Add the egg and vanilla extract to the butter mixture, mixing until smooth and fully incorporated.
05 - Gradually stir in the dry ingredients to the wet mixture, mixing until just combined. Be careful not to overmix.
06 - Fold in grated carrots, oats, and any optional add-ins such as nuts and/or raisins until evenly distributed throughout the dough.
07 - Drop tablespoon-sized portions of dough onto the prepared baking sheet, spacing them 2 inches apart to allow for spreading.
08 - Bake for 10-12 minutes, or until edges are lightly golden and centers are set. Allow cookies to cool on the baking sheet for 5 minutes.
09 - Transfer cookies to a wire rack and let cool completely before frosting or serving.
10 - Beat cream cheese and butter until smooth and creamy. Add powdered sugar and vanilla extract, mixing until fluffy and well combined.
11 - Spread or pipe frosting onto completely cooled cookies as desired.