Hi,
You can use just a regular boiled sugar recipe. Use playdough or plasticene which you can get at Hobby Lobby or Michaels. First you need to know how wide and tall your windows are. You can cut the molds out of playdough or plasticene. Then pour the sugar into them, you can use royal icing for the window frames. Search the other threads in this forum and you will find a recipe for boiled sugar. If you don't find one let me know. If you are pouring or casting sugar you can leave the acid out of the recipe if you like. If you need anymore help let me know.
Regards SugarCreations...