Makes 12 servings
Mix and bake cake according to package directions in a tube or bundt pan, adding 1 tablespoon lemon verbena leaves and 1/2 of zest to batter. Make a glaze with 2 tablespoons lemonade, sugar, remaining verbena and zest. When cake is done, remove from oven, make holes in cake with a fork and saturate with lemonade concentrate; cool in pan for 20 minutes. Invert cake onto serving dish and drizzle with glaze. If desired, decorate with additional fresh or crystallized herb leaves and edible flowers.