Generally, sweet wines are an excellent way to complete a meal, matched with relatively savoury desserts such as almond tart, anything citric and all forms of cheese. They are also great chilled as an afternoon drink, perhaps with fruits and nuts, and simply wonderful with pate/foie gras.
Spanish sweet wines are predominantly made using the Moscatel grape. Moscatel is the same variety which produces, variously, Moscato d'Asti in Piedmont; Passito de Pantelleria in Sicily and many of the muscat wines of Australia, the Rhone ... arguably, the most important great wine variety in world wine history, given the significance of the ship-based trade routes in and around the Mediterranean, and the preservative effects of sugar.
Image courtesy of ©Jason Orton