Mix all wet ingredients (including carrots) together.
Whisk together dry ingredients.
Stir liquids into dry ingredients.
Pour into parchment-lined and oiled 8” or 9” cake pans.
Bake at 350°F/180°C until a toothpick inserted in the center of the cake comes out with a few crumbs on it or for about 25-30 minutes.
Cool, then cut each cake in half, trimming some of the domed tops off the cakes if needed.
Mix cream cheese and butter in the bowl of a stand mixer fitted with the whisk attachment until smooth, scraping down the bowl 2-3 times.
Add in half of the powdered sugar and mix until smooth. Scrape down the bowl, then add in the remaining powdered sugar and salt. Mix until the frosting is smooth.
Add in vanilla and lemon juice then mix until uniform. Use immediately to frost your cake.
Place the first cake on your cake platter, add 2 scoops of frosting on top of it, and spread the frosting so that it covers the cake evenly and live a little of room at the edges of the cake. Repeat with the second, third, and fourth layers of the cake.
Then use the remainder of the frosting to frost all around the side edges of the cake.