Preheat oven to 350 degrees and grease a 9x13 inch baking dish. In a large bowl, beat the first six ingredients until well blended. In another bowl, mix the flour, baking soda, cinnamon, and nutmeg; gradually beat into carrot mixture. Pour mixture into prepared pan.
Bake for 35-45 minutes or until a toothpick inserted in center comes out clean. You can cover it with foil towards the end if the top looks like it's getting too brown. Cool completely in pan on a wire rack.
For the frosting: In a large bowl, beat the cream cheese, butter and vanilla until blended. Gradually beat in confectioners' sugar until smooth adding a little milk if needed. Spread over cooled cake and topped with pecans if desired. Cover and refrigerate until serving.