Preheat the oven to 170° C w/ fan.
Trim & cut the rhubarb into thin slices.
Mix the rhubarb in the casserole w/ sugar, lemon juice & cornstarch.
Mix flour, baking powder & salt.
Add sugar & cubed cold butter & knead it w/ your hands until well mixed.
Add the liquid whipping cream & fold it in w/ a spoon.
Pour the batter over the fruit mix & distribute the batter evenly. You don't need to cover all the rhubarb.
Sprinkle the brown sugar on top.
Bake it in the preheated oven for about 40 min.
It's ready for serving after the oven session - just let it cool for about 10 - 15 min.