In a large bowl, stir together apples and sugar. Add the flour, baking soda and salt; stir well.
In a separate bowl, beat eggs, oil, and vanilla. Stir the egg mixture into the apple mixture, blending until thoroughly moistened. Batter will be very thick! Stir in pecans.
Press batter into a greased 13x9-inch pan. Bake 50 minutes or until cake springs back when lightly pressed.
To make the sauce: Place ingredients in a saucepan and stir. Bring to a boil over medium heat; boil for 3 minutes, stirring constantly. Allow to cool slightly before serving warm with the cake.