Preheat the oven to 350°F (175°C). Grease and flour a 10-cup bundt pan, making sure to coat every corner to prevent sticking.

In a large bowl, combine the sugar, vegetable oil, vanilla extract, and eggs. Whisk until the mixture is smooth and fully blended.

In a separate bowl, stir together the flour, baking soda, cinnamon, and salt. Gradually add the dry ingredients to the wet mixture, mixing gently until just combined.

Gently fold in the diced Granny Smith apples, ensuring they are evenly mixed into the batter. Pour the batter into the prepared bundt pan, spreading it out evenly.

Bake for 55-65 minutes, or until a toothpick inserted into the center comes out clean. Let the cake cool in the pan for 15 minutes before turning it out onto a wire rack to cool completely.

For the caramel glaze, melt the butter in a medium saucepan over medium heat. Add the heavy cream, brown sugar, and salt, stirring until combined. Bring the mixture to a gentle boil, then reduce the heat and simmer for 3-4 minutes, stirring constantly. Remove from heat and stir in the vanilla extract.

Pour the warm caramel glaze over the cooled cake, letting it drip down the sides.

Slice and serve the cake at room temperature or slightly warm. Enjoy!