Marzipan, or sweet almond paste dough, has a recorded history that dates to the Crusades, and may possibly be older. It's been used on its own as a sweet treat, as well as to decorate other dessert items, such as cakes. You may be more familiar with using fondant to cover cakes, but marzipan was used for this task before fondant was created. Like fondant, marzipan dough can be sticky and tricky to work with. Unlike fondant, marzipan does not stretch very well and can be somewhat unforgiving if you make mistakes when covering cakes.
Bring the marzipan and cake to room temperature if they have been refrigerated. Use whatever amount of marzipan will cover the size of cake you have made. It is OK to warm the marzipan by microwaving it on high in 20-second intervals, but simply leaving it on the counter for a few hours or overnight also works.
Sprinkle flour on your counter and rolling pin to prevent the marzipan from sticking. Lay the marzipan in the centre of your counter.
Roll out the marzipan gently, starting from the centre of the dough. Watch and feel with your hands to see if any cracks appear as you roll. If they do, fold the dough back up and roll again until no cracks appear and it begins to flatten smoothly.
Guide the shape of the marzipan as you roll it out by changing rolling directions. For a round cake, start in the middle and then begin rolling the flattened disc of dough in a circle, rather than straight across or up and down. For a square or rectangular cake, roll straight across and up and down.
Stop rolling when the dough has reached a thickness of about ¼ inch. Gently slide an offset spatula under the edges to loosen any places where it may have stuck to the counter. Dust off any excess flour on the surface of the marzipan.
Place the cake on an appropriately sized cake cardboard. Then, slide the marzipan onto a pizza peel to help support its weight and prevent tearing. Position the pizza peel over the cake, then slide the marzipan into position.
Smooth the marzipan into place with your hands and a fondant smoothing tool, going from the centre out to the edges. Fondant smoothing tools resemble plastic irons and can be purchased at craft stores in the cake-decorating aisle, or at baking supply stores. Trim any excess marzipan from the bottoms of the sides of your cake with a sharp, thin-bladed knife.