Preheat the oven to 350 degrees. Grease 2 8-inch round cake pans and line the bottoms with wax paper or parchment. Grease again and dust with flour.
In a large bowl, whisk together the flour, cinnamon, baking soda, baking powder, salt and just 1 cup sugar. Set aside.
With an electric mixer, beat the eggs and 1 cup sugar until the mixture is thick and light (ribbon stage), about 5 minutes.
With the mixer running, gradually add the oil and continue whipping until the mixture is light and fluffy, about 5 minutes.
Gradually stir the flour mixture into the cake mixture, then fold in the carrots and currants (or raisins).
Divide the batter evenly between the two pans and bake the cakes on the same rack in the center of the oven just until set, 30 to 40 minutes, rotating halfway through for even cooking. A toothpick inserted will come out clean when the cakes are done. Remove the pans to a rack until cool before unmolding.
While the cakes are cooling, make the cream cheese frosting.
Cream cheese frosting: With an electric mixer, beat the butter until light and smooth. Add the cream cheese and continue mixing until smooth. Scrape the sides of the bowl often to make sure the contents are completely combined.
Mix in the powdered sugar and vanilla. Add the sugar in three stages, mixing and scraping the sides of the bowl with each addition until the frosting is smooth.
Frost the cake then chill slightly to allow the frosting to thicken before serving.