Open the 1st can of crescent roll dough and lay the dough in the bottom of the prepared baking dish. Be sure to pinch close the perforated sections of the dough. Bake for 10 minutes.
Using a spoon or offset spatula, evenly spread the dijon mustard on top of the bottom roll layer.
Lay 12 slices of the cheese on top of the mustard layer.
Folding the sliced ham in half, evenly layer the ham on top of the cheese layer.
Top the ham layer with the remaining 12 slices of cheese.
Lay the 2nd can of crescent dough on top of the last layer of cheese. Be sure to pinch close the perforated sections.
Using a small heat-safe bowl, whisk together the melted butter, onion powder, and dried Italian seasoning.
Using a pastry brush, generously brush the butter mixture on top of the top layer of crescent dough.
Bake for 20 to 22 minutes, or until the top layer is golden brown. Slice eight 3½ inch by 3 inch sections.