1. Preheat the Oven:

• Preheat your oven to 350°F (175°C).

• Grease and flour a 9×13-inch baking pan to prevent sticking.

2. Make the Sticky Topping:

• In a small bowl, combine brown sugar, melted butter, corn syrup, and cinnamon.

• Stir until smooth and well blended.

• Pour the mixture evenly into the prepared baking pan.

• Sprinkle chopped pecans or walnuts on top, if using.

3. Prepare the Cake Batter:

• In a large bowl, mix the cake mix, water, vegetable oil, and eggs.

• Beat on low speed for 30 seconds, then medium speed for 2 minutes until smooth.

4. Mix the Cinnamon Filling:

• In a separate small bowl, stir together granulated sugar and cinnamon.

5. Assemble the Cake:

1. Pour half of the cake batter over the sticky topping.

2. Sprinkle the cinnamon-sugar mixture evenly over the batter.

3. Pour the remaining cake batter on top, smoothing it evenly.

6. Bake:

• Bake for 40–45 minutes, or until a toothpick inserted into the center comes out clean.

• Allow the cake to cool in the pan for 10 minutes.

7. Invert and Serve:

• Run a knife around the edge of the cake to loosen it.

• Place a large platter or baking sheet over the pan and carefully invert the cake.

• Let the sticky caramel drizzle over the top of the cake.