This one-bowl, one-layer carrot cake is a perfect "mix-and-bake" dessert. It's full of flavor from the shredded carrots, cinnamon and vanilla, and the nuts add texture. The cake is super-moist because it uses oil, and the fresh carrots add moisture too. You don't need any fancy equipment--you can simply mix all of the ingredients together in a bowl with a whisk or spoon (and a fork is the perfect makeshift whisk!). The frosting is super creamy and simple, and you can jazz things up and serve the iced cake from a cake stand, if you want to be fancy.
Spread the nuts in an even layer on a baking sheet. Cook until toasted, 8 to 10 minutes. Give them a shake halfway through so they don't burn.
Meanwhile, prepare your baking pan. A square 8-inch cake pan or a 9-inch round cake pan both work great. You can spray the pan with nonstick baking spray with flour or line the bottom with parchment paper and then grease the pan and the paper.
In a large bowl, whisk the eggs and oil together until combined. Add the milk, sugar, vanilla and salt and whisk until combined. Sift the flour, baking soda, baking powder and cinnamon into the bowl and stir or fold until combined. Add the carrots, raisins and toasted nuts if using and stir or fold until combined.
Pour the batter into the prepared pan and bake until your house smells like carrot cake and a toothpick inserted into the center comes out clean, 35 to 40 minutes. Remove from the oven and cool on a wire rack 15 to 20 minutes. Remove the cake from the pan and cool on the rack completely.
While the cake is baking, make the frosting: Add the softened cream cheese to a large bowl and whisk it until it is smooth (if the cream cheese isn't softened, zap it in the microwave for 5 or 10 seconds).
Add the confectioners' sugar, milk, vanilla, if using, and salt and whisk until smooth. If the frosting is a little too thick, add a tiny bit more milk. If it's too thin, you can add more confectioners' sugar.
Once your cake has cooled (if it's warm it will melt the frosting), spread the frosting evenly over the cake. Tada! Enjoy!