Preheat oven to 400°F. Heat oil in an 8-inch cast-iron skillet over medium-high. Add ham, and cook, stirring often, until crispy and well browned, about 8 minutes. Remove ham from pan, and let cool. Set aside. Wipe skillet clean with a paper towel, and place in oven to heat. 

Combine flour, baking powder, baking soda, and salt in a medium bowl. Add cold butter pieces to flour. Using a pastry blender or 2 forks, cut butter into flour mixture until coarse crumbs form. Place bowl in freezer 10 minutes to chill.

Whisk together pumpkin and butter-milk in a small bowl. Stir in crispy ham. Add buttermilk mixture to flour mixture, stirring until just moistened. Place dough on a floured work surface, and gently pat to 1-inch thickness. Using a 2 1⁄2-inch round cutter, cut dough into 8 biscuits. Remove skillet from oven, and melt 1 tablespoon of the softened butter in hot skillet, swirling to coat. Arrange biscuits in skillet, with sides touching. Melt another 1 tablespoon of the softened butter, and brush over tops of biscuits. Bake in preheated oven until biscuits are puffed and browned, about 15 minutes.

Combine honey and remaining 4 tablespoons softened butter in a small bowl. Serve honey butter with biscuits.