Grease a 13x9x2-inch baking pan; set aside. In a very large bowl, combine flour, sugar, baking soda, salt and cinnamon; make a well in center of dry mixture and set aside.
In a medium bowl, combine eggs, oil and vanilla; stir in apples and nuts. Add egg mixture to flour mixture, stirring just until moistened (batter will be stiff). Spread batter in prepared pan.
Bake in a 350 degrees oven for 50 to 55 minutes or until a toothpick inserted in center comes out clean. Cool in pan on a wire rack for at least 1 hour. Serve slightly warm or at room temperature. If you like, top each serving with sweetened whipped cream and an apple slice. Makes 20 servings.