Preheat your oven to 375°F (190°C). Line a baking sheet with parchment paper or lightly coat with nonstick spray.
In a small bowl, mix the melted butter with the garlic. Set aside.
If using crescent dough, pinch seams together to form one rectangle.
On a lightly floured surface, roll the dough into a 12x8-inch rectangle. Spread a thin layer of mustard over the dough, leaving a 1/2-inch border on the long side farthest from you.
Layer the ham slices evenly over the dough. Sprinkle the shredded cheese on top, then add the Italian seasoning, black pepper, and red pepper flakes if using.
Starting from the long edge closest to you, roll the dough up tightly into a log.
Pinch the seam to seal.
Using a sharp knife or unflavored dental floss, slice the log into 12 equal pinwheels. Place them cut-side up on the prepared baking sheet, spacing slightly apart.
Brush the tops with the garlic butter. Sprinkle with Parmesan if you like.
Bake for 15–20 minutes, until golden brown and the cheese is bubbling.
If the centers look doughy, give them 2–3 more minutes.
Cool for 5 minutes, then serve warm. Great with honey mustard, ranch, or marinara.