Preheat the Oven: Preheat your oven to 325°F (165°C). Lightly coat a 9x13-inch baking dish or two 8-inch round cake pans with grease and dust them with flour.

Mix the Wet Ingredients: In a large mixing bowl, combine the cooking oil and granulated sugar. Incorporate the eggs individually, ensuring each is well mixed before adding the next. Then, stir in the vanilla extract until fully blended.

Combine the Dry Ingredients: In a separate bowl, whisk together the all-purpose flour, baking soda, ground cinnamon, and salt. Slowly incorporate the dry ingredients into the wet mixture, stirring until just combined. Take care to avoid overmixing the batter.

Fold in the Apples and Pecans: Gently fold the chopped apples and pecans into the batter, ensuring they are evenly distributed.

Bake the Cake: Transfer the batter to the prepared baking pan(s) and level it out. Place in the preheated oven and bake for 50 to 60 minutes, or until a toothpick inserted into the center comes out clean. If you’re using round cake pans, start checking for doneness at around 35 to 40 minutes.

Cool the Cake: Take the cake out of the oven and allow it to cool in the pan for roughly 10 minutes. After that, carefully move it to a wire rack to cool completely.

Melt the Butter: In a medium-sized saucepan, heat the unsalted butter over medium heat until it melts.

Add Brown Sugar and Milk: Add the light brown sugar and milk to the melted butter. Mix thoroughly and allow the mixture to come to a boil. Boil for 2-3 minutes, stirring constantly, until the sugar is dissolved and the mixture thickens slightly.

Add Vanilla and Cool: Take the saucepan off the heat and mix in the vanilla extract. Let the glaze cool for about 5 minutes, or until it thickens enough to coat the back of a spoon.

Pour the Glaze: Pour the warm caramel glaze over the cooled cake, spreading it evenly. Let the glaze sit for approximately 15 to 20 minutes to firm up before serving.