German Rhubarb Meringue Cake

1 . Stage

Preheat the oven to 350 degrees F (175 degrees C). Butter a 10-inch springform pan.

2 . Stage

Combine butter, sugar, vanilla sugar, and salt in a large bowl and beat with an electric blender until smooth and creamy. Add eggs one at a time, beating well after each addition.

3 . Stage

Sift together flour and baking powder and mix into the batter, 1/4 cup at a time. Pour batter into the prepared springform pan. Press rhubarb pieces into the batter and sprinkle sugar over the top.

4 . Stage

Bake in the preheated oven until lightly browned, about 30 minutes.

5 . Stage

Meanwhile, beat egg whites in a glass, metal, or ceramic bowl until foamy. Gradually add sugar, continuing to beat until stiff peaks form and meringue mixture is glossy. Remove cake from the oven and spread meringue mixture on top.

6 . Stage

Continue baking until meringue is set and lightly browned, about 15 minutes. Allow to cool in the springform pan.