In a large mixing bowl, stir together the all-purpose flour, sugar, baking powder, ground cinnamon, and baking soda.
Add the finely shredded carrots, the cooking oil, and eggs. Beat the mixture with an electric mixer until it's just combined. Stir in the chopped pecans.
Transfer the carrot mixture to a greased 13x9x2-inch baking pan. Bake in a 350 degree F oven for 40 to 45 minutes or until a toothpick inserted near the center comes out clean. Cool the cake in the pan on a wire rack.
Prepare the Cream Cheese Frosting. Spread the frosting over the cooled cake. Cover and store in the refrigerator. Makes 16 bars.