Grate the carrots and put them in a bowl. Add oil and lemon juice.
Beat eggs together with sugar until fluffy. Fold in flour and nuts, and carrots.
Evenly divide batter into cupcake liners. Transfer to oven and bake on 180C for 25 minutes or until a toothpick inserted in the center comes out clean or with moist crumbs.
For the frosting, combine butter and cream cheese in the bowl of a stand mixer and beat until creamy, well-combined, and lump-free. Add powdered sugar and mix until well combined. Enjoy!