Preheat oven to 350 degrees F. Line a large rimmed baking sheet (or roasting pan) with foil, or coat the pan with cooking spray. Place the ham in the pan.
In a small bowl, mix together the dark brown sugar, Dijon mustard, paprika, cornstarch, and red pepper flake (optional).
Rub brown sugar mixture all over the ham, making sure to get in between the slices.
Next, pour the cola over the ham. Cover the ham loosely with foil and bake for 90 minutes.
Remove from the oven and baste with the juices in the pan.
Place back in the (uncovered) and bake for another 30 minutes.
Remove from the oven and serve!
Cover and bake for 90 minutes
Remove from oven and baste with juices in the pan
Place back in the oven uncovered for another 30 minutes
Remove from the oven and serve with your favorite side dishes!
Notes
A fully cooked spiral ham needs to bake for 10 minutes per pound at 350 degrees.