Preheat oven to 350 degrees.
Trim excess fat or skin from ham. Score ham in a criss cross or diamond cut along the top of the ham.
Place the ham in a roasting pan or baking dish.
In a small bowl combine brown sugar, dijon mustard, and garlic powder until combined. Rub mixture all over ham.
Pour can of cola (coke) around the bottom of the ham, directly into pan. Do not pour on top of the ham as this will wash all of the rub off.
Cover ham loosely with foil or lid and place roasting pan in middle rack of oven. Bake for 15 minutes per pound. Remove from oven and let rest for 15 minutes.
