My Small Carrot Cake is tender, warmly spiced, and perfectly sized for a few—finished with creamy frosting and ready in under an hour.
Preheat the oven to 350°F (180°C). Butter and line a 6 inch (15 cm) round cake pan with parchment. Butter the parchment, dust with flour, and tap out the excess. Set aside.
In a small bowl, whisk together the flour, cinnamon, nutmeg, baking soda and salt.
In a medium bowl, whisk together the egg, brown sugar, melted butter, orange zest (if using), and vanilla extract until thickened and smooth, about 2 minutes
Fold the dry ingredients into the wet ingredients until almost combined, then add the carrots and walnuts (if using) and mix just until incorporated.
Spread the batter evenly into the prepared pan.
In a medium bowl, whisk the cream cheese and butter together until smooth, then mix in the milk and vanilla extract.
Spread the frosting over the top of the cake, leaving the sides exposed. Scatter over extra toasted, chopped walnuts if you wish.