Preheat oven to 350 degrees. Grease a 9x13-inch pan and set aside.
In a medium bowl, combine 3 cups all purpose flour, 2 cups sugar, 1 teaspoon baking soda 1 teaspoon salt and 1 teaspoon cinnamon.
In a large bowl, beat 4 eggs until light and foamy. Add 1 cup canola oil and 2 teaspoons vanilla and mix well.
Stir in the flour mixture with a spoon and continue stirring the batter until the flour disappears.
Add the 3 cups finely chopped apples and 1 cup pecans or walnuts; mix well.
Scrape the batter into prepared pan and bake for 40-45 minutes, or until a toothpick inserted in the center comes out clean. Set the cake on a wire rack.
While the cake is still hot, prepare the glaze.
Combine 1 cup packed light brown sugar, 6 tablespoons butter, 1 teaspoon vanilla and 2 tablespoons heavy cream in a medium saucepan.
Cook over medium heat, stirring often, until the mixture comes to a gentle boil. Continue cooking for 3 minutes.
Spoon the hot glaze over the still warm cake.
Let the glazed cake cool completely before serving straight from the pan.