Mix oil, eggs, and sugar. In a separate bowl, combine flour, salt and spices. Add to wet ingredients then stir in carrots. Bake in a greased 11 x 17 pan at 350 for 35-40 minutes until a toothpick inserted in the centre of the cake comes out clean. Cool completely before frosting.
For the Frosting:
Cream room temperature butter with cream cheese and then add jam. Incorporate icing sugar a bit at a time.