Heat oven to 350°F. Spray 9x2-inch round cake pan with cooking spray. Combine topping ingredients in a medium saucepan and bring to a boil over medium-high heat. Boil 1 minute or until sugar is dissolved. Pour into bottom of pan. Beat butter in large mixing bowl with electric mixer at medium speed for 2 minutes or light and fluffy. Add ¾ cup sugar and beat 2 to 3 minutes or until very light and fluffy. Add eggs, one at a time, beating well after each addition. Whisk together flour, ground ginger, baking powder, baking soda and nutmeg in a medium bowl until well-blended. On low speed, alternately beat in flour and sour cream in 3 parts, beginning and ending with flour, being careful not to over beat. Spoon batter over topping and gently spread to cover. Bake 30 to 35 minutes or until wooden pick inserted in center comes out clean. Cool 10 minutes on wire rack and invert onto serving plate. Cool completely. Makes 12 servings