Preheat oven to 350-degrees. Spray an 8-inch nonstick round cake pan with vegetable oil spray. Cut a circle of parchment paper or wax paper to fit the bottom of the pan. Place paper in pan. If using wax paper, spray the top with vegetable oil spray.

Place the pan in the middle of a 12 x 17 x 1-inch jelly-roll pan and fill jelly-roll pan half full with warm water, or place cake pan in a baking pan (the bottom of a broiler pan works well) and add warm water to a depth of 1-inch.

Bake for 40 to 45 minutes, or until a toothpick inserted in the center of cake comes out clean. Remove cake pan from water and let cool on a wire rack for 10 minutes. Carefully invert onto a plate (it is not necessary to loosen sides first) and remove paper. Let cool for 15 minutes. While cake is cooling, heat preserves in a small saucepan over low heat, stirring occasionally.

Top the cake with a thin coating of the preserves. Sprinkle with about half the raspberries. Cut the cake into ten pie-shaped slices. Spoon remaining preserves on each dessert plate. Place each cake slice on preserves. Top with remaining raspberries, then dust lightly with powdered sugar.

For a more formal presentation, place raspberries in a ring around the top of the cake before cutting. Sprinkle any remaining berries on the dessert plates.