Preheat your oven to 350°F (175°C). Grease and flour a 9x13 inch cake pan.
In a large bowl, whisk together the flour, sugar, baking powder, baking soda, cinnamon, and salt.
Add the oil, eggs, and vanilla extract. Mix until well combined.
Fold in the grated carrots.
Pour the batter into the prepared cake pan.
Bake for 40 minutes or until a toothpick inserted into the center comes out clean.
Let the cake cool completely before frosting.
For the frosting, beat the cream cheese and butter together until smooth. Gradually add the powdered sugar and vanilla extract, and beat until creamy.
Spread the frosting over the cooled cake. Slice and serve.