Upside down rhubarb cake
Preheat the oven to 180°C (350°F).
In a bowl, combine the rhubarb, 15 ml of flour and the brown sugar.
Spread the mixture in a buttered square pan.
Prepare the cake following the instructions on the envelope.
Pour the cake mix over the rhubarb mixture.
Put the cake in the preheated oven and cook for 40 to 45 minutes.
Once the cake is cooked, remove from the oven and let cool in the pan for 5 minutes.
Turn over onto a plate and serve with a scoop of vanilla ice cream.