Heat oven to 350°F. Grease bottom only of 8-inch square pan. In large bowl, combine flour, wheat germ, brown sugar, baking powder, baking soda, ginger, cinnamon and allspice; mix well. Add all remaining gingerbread ingredients; blend well. Pour into greased pan.
Bake at 350°F. for 30 to 40 minutes or until toothpick inserted in center comes out clean.
Meanwhile, in medium saucepan, combine sugar and cornstarch. Gradually stir in hot water. Cook over medium heat until mixture comes to a boil and is slightly thickened and clear, stirring constantly. Stir in lemon juice and lemon peel. Serve warm sauce over warm gingerbread.