Preheat the oven to 175° C and grease the muffin tin or line it with paper cups.
FOR THE Dough: In a large bowl, mix flour, baking powder, baking soda, cinnamon and salt.
In a second bowl, beat the oil with the eggs and brown sugar until foamy.
Add the liquid mixture to the flour mixture while stirring until everything is mixed. Fold in carrots and nuts.
Pour into tins and bake at 175° C for 25 minutes. Allow to cool well before coating with the Frosting.
FOR THE FROSTING: Mix all ingredients well with a hand mixer and brush the cupcakes with it. Now they can be decorated with sugar Easter eggs or any other decoration.