In a medium-size bowl, whisk together the flour, oats, baking soda, salt, fennel seed, cinnamon, ginger and nutmeg. Set aside.
In the bowl of a stand mixer fitted with the paddle attachment, mix both oils with the sugar. Once combined, add in the eggs one at a time. Next, add the flour mixture in batches on low speed. Once fully combined, turn off the mixer and remove the bowl from the stand. Using a rubber spatula, fold in the carrots, raisins, pecans and orange zest.
Pour the batter into a prepared 13x9-inch baking pan and bake 45-50 minutes. Remove cake from oven and let cool.
Place the cream cheese and butter into the mixer bowl and beat with a paddle attachment until smooth. With the mixer on low speed, add the remaining two cups of confectioners’ sugar a spoonful at a time until completely incorporated. Once all the sugar has been added, add the vanilla and salt. Spoon the cake over top of the cake and then spread evenly with a spatula.
Grant Melton is an Emmy Award-Winning Producer of the Rachael Ray Show, food writer and recipe developer. He's a contributor to Food52, Food Network Kitchen and Rachael Ray Every Day Magazine. His favorite food is chocolate chip cookies (with salt.)