In a medium bowl, whisk together egg and sugar. Add yogurt, applesauce, oil, and vanilla; whisk until blended. Make a well in the center of reserved flour mixture, add egg mixture and mix with rubber spatula just until dry ingredients are moistened. Reserve 1 cup batter for topping. Spread remaining batter in a prepared pan.
To make the filling and topping: In a medium bowl, combine blueberries, raspberries, coffee powder, and fruit spread. With the rubber spatula, stir gently to coat berries with fruit spread. Spoon berry filling over batter in a pan. Drop mounds of reserved batter by tablespoonfuls over berry filling. In a small bowl, combine sugar and cinnamon; sprinkle over top of coffee cake.
Bake the coffee cake until golden and a toothpick inserted in the center comes out clean, 40 to 45 minutes. Let cool in a pan on a wire rack about 30 minutes.
To make the glaze: Sift confectioners’ sugar into small bowl. Add vanilla and 2 tsp. milk; whisk to blend. Add just enough milk until the glaze can be drizzled.
Drizzle the glaze decoratively over the top of coffee cake. Serve cold and plain or with other desserts.