Instructions:
To start, preheat your oven to 350°F (175°C) and grease a 9x13-inch baking dish or line it with parchment paper. In a large bowl, mix together the flour, granulated sugar, brown sugar, baking soda, baking powder, salt, cinnamon, and nutmeg. In another bowl, whisk the eggs, then add the vegetable oil and vanilla extract, stirring until well combined. Pour the wet ingredients into the dry mixture and stir just until blended. Fold in the grated carrots and, if using, the chopped nuts. Once the batter is fully mixed, pour it into the prepared pan and spread it evenly. Bake for 30 to 35 minutes, or until a toothpick inserted into the center comes out clean. Let the cake cool completely before adding frosting, if desired.