01 - Place butter in medium saucepan over medium heat. Cook, stirring constantly, until butter foams, browns, and smells nutty, approximately 4–6 minutes. Immediately pour into large mixing bowl and cool 10 minutes.
02 - Add brown sugar and granulated sugar to browned butter; whisk until fully combined. Stir in eggs and vanilla extract until mixture is smooth and creamy.
03 - In separate bowl, whisk together flour, baking soda, baking powder, salt, cinnamon, nutmeg, and ginger until evenly distributed.
04 - Add dry ingredients to wet mixture. Stir until just combined—do not overmix. Fold in oats, grated carrots, walnuts or pecans, and raisins if using.
05 - Cover bowl and refrigerate dough 30 minutes for chewier texture. This step is optional but highly recommended for best results.
06 - Preheat oven to 350°F. Line two baking sheets with parchment paper.
07 - Scoop dough into 2-tablespoon balls, placing 2 inches apart on prepared baking sheets.
08 - Bake 11–13 minutes, until edges are set and centers appear slightly underbaked. Cool on baking sheet 5 minutes, then transfer to wire rack to cool completely.
09 - Beat softened cream cheese and butter with powdered sugar and vanilla extract until smooth and creamy. Drizzle over cooled cookies.