Preheat your oven to 350°F (175°C), and line a cupcake tray with vibrant paper liners.

In a large mixing bowl, whisk together the eggs, brown sugar, neutral oil, sour cream, and mashed pineapple until smooth.

In another bowl, whisk together the flour, baking powder, baking soda, cinnamon, and salt.

Gradually add the dry mixture to the bowl of wet ingredients, folding gently.

Fold in the shredded carrots and chopped nuts until evenly distributed.

Fill each cupcake liner three-quarters full and bake for 18–20 minutes.

Cool the cupcakes in the pan for 5 minutes, then transfer to a wire rack to cool completely.

For the walnut crumble, pulse together nuts, flour, brown sugar, and salt, then add butter and process until sandy.

Spread the crumble on a baking sheet and bake until golden brown, about 10 minutes.

In a mixing bowl, beat the cream cheese until smooth, then gradually mix in powdered sugar and vanilla.

Add heavy whipping cream and beat until stiff peaks form.

Frost the cooled cupcakes with cream cheese mixture and top with walnut crumble.

Chill the frosted cupcakes for about 30 minutes before serving.