Fresh sweet plums and butter streusel make this easy traditional German cake perfect for your next work potluck, family dinner or afternoon snack!
To make the dough, mix yogurt (or quark), milk, sugar, oil, vanilla extract, flour, salt, and baking powder in a large bowl.
Once dough forms a ball, turn onto a floured surface and knead several times until dough becomes smooth.
Press dough into prepared jelly roll pan (14.5 x 10 inches). Sprinkle the cream of wheat over the dough.
Cut plums in half and then into 3 or 4 slices. Arrange the slices on the dough so they overlap slightly (skin side touching the dough).
To make the streusel topping, mix the flour, sugar, and cinnamon together. Then rub the butter into the flour mixture. Sprinkle the streusel topping over the plums.
Bake for 30-40 minutes or until crust and streusel are lightly browned.