1. Preheat your oven to 350°F (175°C) and grease a baking dish.
2. Prepare the cake batter by mixing butter pecan or yellow cake mix with eggs and any other required ingredients according to the package instructions.
3. Pour the batter into the prepared baking dish and bake for about 15-20 minutes until it is partially set but not fully cooked.
4. While the cake is baking, prepare the pecan topping by mixing melted butter, brown sugar, corn syrup, and chopped pecans in a bowl.
5. Carefully spread the pecan mixture evenly over the partially baked cake.
6. Return the cake to the oven and bake for an additional 15-20 minutes until the topping is caramelized and the cake is fully cooked.
7. Remove the cake from the oven and allow it to cool slightly before slicing.
8. Serve warm or at room temperature, optionally topped with vanilla ice cream or whipped cream.
9. Store any leftovers at room temperature for a few days or reheat in the microwave for a warm serving.