Simple Rhubarb Cake

Preheat the oven to 350°F (175°C). Grease and flour a 9x13-inch baking dish.

Prepare the yellow cake mix according to package directions. Pour the batter into the prepared baking dish and spread evenly.

Distribute the chopped rhubarb evenly over the cake batter. Do not stir; the rhubarb will sink slightly as the cake bakes.

Combine the sugar and heavy cream in a small bowl, stirring until the sugar begins to dissolve.

Pour the sugar and cream mixture evenly over the rhubarb and batter. Work quickly so the topping covers the entire surface.

Bake for 45 minutes until the cake is golden brown and a toothpick inserted into the cake portion comes out clean.

Remove from the oven and allow the cake to cool for at least 10 minutes before serving. The topping will be custard-like and may continue to set as it cools.