Preheat oven to 350°F (175°C) and line two baking sheets with parchment paper.
In a medium bowl, whisk together flour, baking soda, salt, cinnamon, and ginger.
In a large bowl, cream together 1/2 cup butter, brown sugar, and granulated sugar until light and fluffy.
Beat in the egg and 1/2 teaspoon vanilla extract until well combined.
Gradually add the dry ingredients to the wet ingredients, mixing until just combined.
Fold in the grated carrots, pecans, and raisins using a spatula.
Drop rounded tablespoons of dough onto the prepared baking sheets, spaced 2 inches apart.
Bake for 10 to 12 minutes or until the edges are lightly browned and the centers are set.
Transfer cookies to a wire rack and allow to cool completely.
In a separate bowl, beat cream cheese and 2 tablespoons butter until smooth.
Gradually add powdered sugar and 1/2 teaspoon vanilla extract to the cream cheese mixture, beating until creamy.
Frost the cooled cookies with the cream cheese mixture before serving.