1. Preheat the oven to 350°F degrees. Grease the bottom of a 9-by 13-inch baking pan and line it with parchment paper. Peel and cut the apples from the core. Cut the apples into 1/2 inch pieces.
2. In a large bowl, lightly whisk the eggs and the sugar until combined. Switch to a spatula and stir in the oil, walnuts, apples and raisins. Sift together the flour, cinnamon, salt and baking soda. Stir it into the egg mixture.
3. The batter will be thick. Spread the batter into the prepared pan. Bake until a skewer inserted in the middle comes out clean, about 45 minutes. Cool completely at room temperature.
4. Run a knife around the inside edge of the pan to loosen the edges of the cake from the pan. Place a cutting board on top of the pan. Invert the cake and the board. Remove the pan and carefully peel off the parchment paper. Cut into 12 pieces. Place right side up.
5. Serve with vanilla ice cream, crème fraiche or whipped cream. Caramel sauce tastes great too. This cake stays fresh for days. Store at room temperature wrapped in plastic wrap or foil.
Directions for caramel sauce:
1. Mix the brown sugar, half-and-half, butter and salt in a saucepan over medium-low heat.
2. Cook while whisking gently for 5 to 7 minutes, until it gets thicker. Add the vanilla and cook another minute to thicken further.
3. Turn off the heat, cool slightly and pour the sauce into a jar. Refrigerate until cold.