Stir homemade caramel sauce into the cupcake batter and add it to the frosting to prove once again that spice cake and caramel are a match made in heaven.
Heat oven to 350 degrees F. Line sixteen 2-1/2-inch muffin cups with foil liners. Coat lightly with cooking spray.
Place 1/3 cup water near stove. Heat sugar and 2 tablespoons water in small saucepan over medium-high heat until sugar starts to dissolve, 3 to 4 minutes. Swirl pan constantly as mixture starts to turn golden in color. When mixture begins to smoke, turns amber-colored and sugar is dissolved, 1 to 2 minutes, remove from heat. Watch very carefully during last stage, because sugar mixture will turn very quickly.
Very carefully add 1/3 cup water in 3 additions to saucepan, holding pan at arms length, to avoid spattering; mixture is very hot. Stir until caramel is dissolved, returning to heat if needed. Pour into 1-cup glass measuring cup. Add water to equal 3/4 cup if needed. Let stand until cooled to room temperature. Use 1/2 cup for batter and 1/4 cup for frosting.
Stir together flour, baking powder, baking soda, ginger, cinnamon and salt in small bowl.
Beat butter and sugar in bowl until light and fluffy, 1 minute. Beat in egg and sour cream until blended. Alternately fold in flour mixture and 1/2 cup cooled caramel mixture in 3 additions, beginning and ending with flour. Spoon into muffin cups.
Bake in 350 degree F oven 25 minutes or until wooden pick inserted in centers comes out clean. Cool in pan on rack 5 minutes. Remove cupcakes from pans; cool completely on wire rack.
Beat butter in medium-size bowl until smooth. Gradually beat in confectioners sugar and remaining 1/4 cup caramel mixture; beat 1 minute or until creamy. Frost cupcakes. Garnish with currants, grapes and gooseberries if desired.