Gather the ingredients. Position a rack in the middle of the oven. Preheat the oven to 350°F.
Grease with unsalted butter one or two 9-inch round cake pans, line the bottom with parchment paper, and then grease the top.
The Cake Batter
In a mixing bowl, sift the 260 g all-purpose flour. Then proceed to whisk the 2 tsp. baking soda, 1/2 tsp. salt, and 1 1/2 tsp. ground cinnamon until very well blended.In a separate mixing bowl, whisk the 1 1/4 cups vegetable oil, 200 g sugar, 190 g brown sugar and 1 tsp. vanilla extract. Add the 4 eggs, one at a time, whisking after each one.
Switch to a large rubber spatula. Scrape the sides and bottom of the bowl, then add the dry ingredients in three parts, gently stirring until they disappear and the batter is smooth. Stir in the 300 g carrot and 120 g pecans (optional).
The Cooking
Divide the cake batter between the prepared cake pans. If only one pan, do it in two waves. Bake at 350°F until the tops of the cake layers are springy when touched and when a toothpick inserted into the center of the cake comes out clean, 40 to 45 minutes.
Cool the cakes in the pans for 15 minutes, then carefully turn the cake layers out onto cooling racks. Remove the parchment paper and cool completely.
The Cream (while the cake is cooking)
In a large mixing bowl, beat the 225 g cream cheese with a handheld mixer on medium speed until smooth and creamy, about 1 minute.
Sift the 140 g powdered sugar and 2 tsp. cornstarch over the cream cheese to remove lumps and beat them together. Pour in the 1/3 cup heavy cream. Beat on medium speed for 2 to 3 minutes or until the frosting is whipped and creamy. This frosting resembles the texture of whipped cream. Chill covered until ready to frost the cake.
When the cake layers are completely cool, frost the top of one cake layer and place the second cake layer on top. Add the remaining frosting to the top of the carrot cake and use a small spatula to swirl the frosting around. Leave the sides of the cake unfrosted
Add the remaining frosting to the top of the carrot cake and use a small spatula to swirl the frosting around. Leave the sides of the cake unfrosted.
The Serving
Finish with 50 g pecans and/or 50 g dark chocolate on top to taste. Carrot Cake is best served sliced into generous pieces alongside a cup of coffee or tea for a delightful treat.