I hope it turns out well.
As a backup, why not get along to your local Italian deli and hunt out a bottle of Marsala All Uovo. Based on Marsala wine it is sweetened, fortified and flavoured with various other aromatic ingredients, often vanilla but other variations like almond, cinnamon or even citrus.
Many lovers of sweet wine adore it. I don't often drink it myself. It is a little too sweet for my taste, although it goes well with sweet desserts. It makes a brilliant addition to some Italian recipes like Tiramisu.
PS Be careful not to get simple Marsala, which is really a sherry variant.