Cut the muffuletta loaf in half lengthwise.
Generously brush both halves with the oil from the olive salad.
Layer as such: half of the salami on the bottom, then the mortadella, mozzarella, capicola, provolone, and remainder of the salami. Top all of this with the olive salad.
Add the top of the bread back on and press down. It's good to go as-is, but some people leave it compressed for an hour or more. Some people wrap it up tightly and let it sit overnight.
Cut the sandwich into quarters. Moan as you eat each bite.
Recipe adapted from Nola Cuisine. Thanks, Danno!