In a small bowl add the melted butter to the tomato paste and quickly stir together until fluffy. 

Stir in the remaining seasonings; set aside. 

Heat a large nonstick skillet over medium heat; add the pepperoni slices, keep in a single layer, cook for 2 minutes on each side, or until the slices have curled up and begin rendering.  Cook up as much pepperoni as you think you will use; for mine I used 8 slices per sandwich, 48 slices of pepperoni total for 6 sandwiches. 

Transfer cooked pepperoni onto a few layers of paper towels to drain; wipe out pan. 

Divide the pizza butter amongst the 6 sandwich bottoms. Top with a few slices of cheese, the pepperoni, and another slice or two of cheese – this makes everything hold together when grilled. 

Place on the sandwich tops.  

Grill 2-3 at a time, brush the top of the bread with melted butter then place buttered-side down; butter the remaining side.  Keeping a medium heat as to not scorch the bread before the middle melts, grill until golden brown – about 2-3 minutes on each side. 

Cool for 1-2 minutes before slicing, then serve and eat immediately!