Follow the steps in order for the best result.
Begin by preheating your oven to 350 degrees Fahrenheit.
Prepare a 13x9 inch baking pan by lightly coating it with cooking spray to prevent sticking.
In a mixing bowl, cream together the light brown sugar and eggs until the mixture is smooth and well combined.
Gradually incorporate the Bisquick into the sugar and egg mixture, mixing until everything is thoroughly blended.
Fold in the pecan pieces, vanilla extract, and flaked coconut, ensuring they are evenly distributed throughout the batter.
Pour the prepared batter into the greased 13x9 inch baking pan, spreading it out evenly.
Bake in the preheated oven for approximately 30 minutes, or until the cake is set.
Important Note: This cake is known for its unique appearance. It will rise dramatically in the oven and then gently collapse in the center as it cools. This is perfectly normal!
Serve the cake warm, either on its own or accompanied by a dollop of whipped cream or a scoop of your favorite ice cream.