Combine granulated sugar, flour, baking soda, 2 teaspoons cinnamon and salt in a large mixing bowl. In a separate mixing bowl, combine eggs, apples, oil and vanilla. Add mixture to the dry ingredients, and stir just until well mixed. Batter will be thick.
Pour cake batter into greased 13 x 9-inch pan. Sprinkle with brown sugar and remaining cinnamon.
Bake 50 to 60 minutes, or until a toothpick inserted in center comes out clean.
To make Caramel Sauce :
Combine butter, sugars, and evaporated milk in medium saucepan over medium high heat. Stirring constantly, bring to a boil for 1 minute. Add cinnamon and vanilla. Cool.
Cut cake and serve with caramel sauce. If desired, top with ice cream or whipped topping.