Preheat oven to 400°F with oven rack one above the bottom. Ham must be completely thawed. If skin is present, remove; leaving as much fat as possible. Score fat criss-cross. Pack brown sugar till you cannot see top of ham and no more will stick.
Place ham uncovered in oven for approx. 20 min or till the brown sugar begins to caramelize. At this point gently pour the can of coke over the ham and return to oven uncovered lowering the heat to 350 or 375°F (depending on your oven). Baste and rotate the pan every 20 min. When the top is candied and caramelized approx. 2.5 hours, then your ham will be done.
Let sit for 10 min. before slicing. If ham begins to brown quickly; loosely tent with foil between basting, removing foil the last 20 min.