Preheat the oven to 350℉ and prepare two muffin tins with 18 cupcake liners.

Whisk together the eggs, brown sugar, granulated sugar, vanilla, and oil in a large bowl. Add the shredded carrots and sour cream and stir until fully mixed.

Whisk together the flour, baking soda, salt, and spices until all are incorporated. Add to the bowl of wet ingredients and mix just until no streaks of flour remain.

Evenly distribute the batter between all 18 liners, filling each cup to the top with batter. Bake the cupcakes in the preheated oven for 25-30 minutes or until a tester inserted into the center comes out clean. Let the cupcakes cool fully before frosting them.

Heat the butter in a heavy saucepan over medium-low heat until melted. Continue cooking until the butter is a deep brown color. Remove from the heat and transfer to another bowl to cool down until cool to the touch yet not solidified.

Cream the softened cream cheese on high speed for 1 minute. Add the liquid cooled browned butter and cream until fluffy. Add the powdered sugar and mix on low until incorporated before increasing the mixer to high and beating for 2 minutes until fluffy.

Frost the cooled cupcakes using a piping bag fitted with your desired piping tip (I used a Wilton 1M open star tip). Enjoy!