Preheat oven to 350ºF. Butter and flour the bottom of a 9-inch spring form pan.
Beat the egg yolks with 3/4 cup sugar until light in color and doubled in volume. Stir in milk, vanilla, flour and baking powder.
In a small bowl, beat egg whites until soft peaks form. Gradually add remaining 1/4 cup sugar. Beat until firm but not dry.
Fold sweet potato then egg whites into yolk mixture. Pour into prepared pan.
Bake at 350ºF for 45 to 50 minutes or until cake tester inserted into the middle comes out clean. Allow cake to cool for 10 minutes.
Loosen edge of cake with knife before removing side of pan. Cool cake completely and place on a deep serving plate. Use a fork or cake tester to pierce surface of cake.
Mix together condensed milk, evaporated milk and 1/4 cup of the whipping cream. Discard 1 cup of the measured milk mixture or cover and refrigerate. Pour remaining milk mixture over cake slowly until absorbed.
Whip the remaining whipping cream until it thickens and reaches spreading consistency. Frost cake with whipped cream and garnish with cherries. Keep refrigerated before serving.