Combine all of the cake ingredient sin a large bowl. Beat until smooth. Pour into a greased jelly roll pan (15x10x1-inch baking pan). Bake for 30-35 minutes, until a tester inserted into the center of the cake comes out clean. Remove cake to a rack to cool completely.
For the frosting, beat the cream cheese and butter until smooth. Add the powdered sugar, 1/2 cup at a time, beating well after each addition. Stir in the vanilla. Spread the frosting over the cooled cake, and sprinkle with the 1/2 cup chopped pecans.