In a large pot, stir together water and sugar over medium heat until sugar dissolves and mixture comes to a simmer. Add 1 1/2 pounds large diced apples and cook about 15 minutes at a low simmer or until apples are very tender. Stir occasionally. Let cool.
In another non-reactive larger pot, melt butter over medium heat and saute ginger about 3 minutes to release its flavor; don't let it burn. Stir in applesauce, white wine, brandy and heavy cream. Stir in cooked apples. Remove from burner and let everything cool to room temperature.
In a food processor fitted with the metal blade, process apple mixture with ice cream (in batches if necessary) until very smooth. Pass everything through a fine sieve into a large bowl. Discard any solids that remain in sieve. Whisk in cinnamon and yogurt and refrigerate several hours or overnight until well chilled, covering when cool. Stir well before serving. Garnish each serving with 1/4 cup fine-diced apples.