Easy Jam Sponge Cake Recipe

1. Preheat oven to 350 degrees F.
2. Line bottom of 9-inch square cake pan with buttered wax paper; dust with flour.
3. Combine egg, egg yolk, and confectioners' sugar in mixing bowl. Beat with electric mixer until very thick and creamy.
4. Sift flour and salt together into seperate bowl; carefully fold flour into egg mixture. Add vanilla.
5. Pour batter into prepared pan; bake for 30 minutes. Cool in pan on wire rack for 5 minutes, then turn out onto rack and cool completely.
6. Split cake in half crosswise; spread jam between layers. Place layers together again; dust top of cake generously with confectioners' sugar. Serves 8.