Preheat the oven to 350 degrees F.
In the bowl of an electric standing mixer, combine the flour, sugar, baking soda, baking powder, cinnamon, nutmeg and salt.
Mix on the slow speed to combine.
In a large measuring cup, whisk together the oil, eggs, and vanilla.
Pour the egg mixture into the dry ingredients, and add the carrots.
Mix on the slowest speed until evenly blended.
The batter will be very thick.
Fold in the raisin and pecans.
Butter and flour a 10-inch round cake pan with 3-inch sides.
Scoop the batter into the prepared pan, and smooth the top.
Bake for 65 to 70 minutes, or until the sides begin to shrink away from the pan and a tooth pick inserted into the center of the cake comes out clean.
Cool on a rack to room temperature.
While the cake is baking, make the frosting.
In a large bowl, beat the cream cheese, butter and super fine sugar vigorously with a wooden spoon until fluffy.
Stir in the orange zest.
Run a small knife around the edge of the cake pan to release the sides, and turn out onto a work surface.
Slice the cake horizontally into three 1-inch layers, using a long, serrated bread knife and placing your hand atop the cake to help guide the knife evenly.
Turn the cake several times to be sure you are cutting even layers.
(Take care that the cake is completely cool before you frost it, or the warmth of the cake will melt the frosting on contact.)
Spread one cake layer with about a quarter of the frosting; then top it with the second cake layer, matching up the edges.
Spread with another quarter of the frosting.
Cover with the third cake round, and frost the top and sides of the cake evenly with the remaining frosting.
Refrigerate for at least 1 hour, and up to 24 hours, to firm the frosting.
For the best flavor, allow to return to room temperature before serving.
Dust generously with confectioners sugar, and cut into wedges.