Preheat your oven to 350°F (175°C) and position a rack in the center. Line a 9x9 inch square metal pan with foil or parchment paper and lightly grease it. This will help in easy removal of the bars once baked.

In a large bowl, whisk together the melted butter, brown sugar, and granulated sugar for about one minute until well combined. Then, whisk in the egg, egg yolk, and vanilla extract until smooth.

In a separate bowl, mix the flour, cinnamon, ginger, nutmeg, salt, and baking powder. This ensures that the spices and leavening agents are evenly distributed.

Gradually add the dry ingredients to the wet mixture, whisking until just combined. Be careful not to overmix, as this can lead to dense bars! Tap the excess batter off the whisk and set it aside.

Using a wooden spoon or silicone spatula, gently fold in the shredded carrots and chopped pecans into the batter. This adds texture and flavor to your bars.

Spread the batter evenly in the prepared pan. Bake for 22-26 minutes, or until a toothpick inserted into the center comes out clean. The bars will rise slightly but remain flat. Once baked, place the pan on a wire rack to cool completely.

For the frosting, beat the softened cream cheese and butter together using a hand mixer or stand mixer with the paddle attachment until smooth. Gradually add the powdered sugar and vanilla extract. If the frosting is too soft, you can add a bit more powdered sugar or chill it in the fridge for about 20 minutes to firm it up.

Once the bars are completely cool, spread or pipe the frosting on top. If you like, sprinkle with additional chopped pecans for garnish. For a fun presentation, consider cutting the bars first and then piping the frosting in a zigzag pattern on top.

Store the bars in the refrigerator and allow them to come to room temperature for about one hour before serving. This will enhance the flavors and texture.