4 cups (1 L) rhubarb, sliced into 1/2 inch (1 cm) cubes
2 teaspoons (10 ml) cornstarch
1/2 cup (125 ml) brown sugar
1 1/4 teaspoon (6.25 ml) baking powder
1 teaspoon (5 ml) salt
1 lemon (zest and juice)
4 eggs
1/3 cup (85 ml) yogurt
Preparation
Preheat the oven to 325°F (165°C). Grease and flour a 9-inch round springform pan. Line the bottom of the pan with two layers of aluminum foil and place the pan on a baking sheet.
In a bowl, combine the flour, salt, and baking powder. Set aside. In a saucepan, heat 1/2 cup (125 ml) of sugar with 1/4 cup (60 ml) of butter, whisking until it comes to a boil (about 2 minutes).
In a bowl, combine the cornstarch with the rhubarb and 1/2 cup (125 ml) of sugar. In another bowl, using an egg beater, mix the butter with the remaining sugar and lemon zest for about 4 minutes. Add the vanilla and mix well. Add the eggs one at a time, mixing well between each addition. Add the yogurt and then the lemon juice. Mix well until the mixture is homogeneous. Reduce the speed of the mixer and add the flour mixture. Mix well until the mixture is homogeneous.
Pour the caramel (brown sugar and melted butter) into the bottom of the cake pan. Add the rhubarb and its juice, and pour the batter on top so that it completely covers the rhubarb. Spread the batter evenly. Place in the oven and bake for 1 hour and 15 minutes, or until the batter is firm to the touch.
Once cooked, remove the cake and place it on a wire rack for 15 minutes to allow it to cool. Run a knife around the edge of the cake, place a plate on top, and quickly flip it over. Remove the cake from the pan while it is still warm, otherwise it will stick to the pan.
