Preheat your oven to 350°F (175°C) and grease a 9x13-inch baking dish.

In a large bowl, whisk together flour, granulated sugar, light brown sugar, baking soda, salt, and cinnamon.

In another bowl, mix eggs, vegetable oil, and sour cream until well combined.

Peel and grate the apples, then set them aside.

Make a well in the center of the dry ingredients and pour in the wet ingredients. Stir until just combined.

Fold in the grated apples.

Pour the batter into the prepared baking dish and spread it evenly.

Bake for 28-32 minutes, or until a toothpick inserted into the center comes out clean.

While the cake is baking, prepare the caramel topping. In a saucepan, melt butter over medium heat. Add brown sugar, heavy cream, salt, and vanilla extract. Stir until the sugar dissolves and the mixture comes to a boil. Let it boil for 1 minute without stirring.

Once the cake is done, pour the caramel topping evenly over the hot cake. Let it cool for 10 minutes before serving.