Cook the prosciutto as you would bacon in a microwave for about 30-45 seconds, depending on the strength of your microwave. It will continue to crisp as it cools,or you can place the prosciutto in a non-stick skillet on medium heat and cook about 1 minute on each side. Remove from the pan, the prosciutto will continue to crisp as it cools.When cool coarsely chop. Place the flour, sugar, baking powder and salt in the bowl of a stand mixer. Using the paddle attachment mix for 30 seconds to combine te ingredients.
Add the cubed butter to the flour mixture and mix on low for 2½ minutes.
Add the chopped crispy prosciutto, asiago cheese, chives and black pepper if using. Mix on low until combimed. Anbout 15-20 seconds.
With the mixer running on low gradually pour in the cream and mix until the dough justcomes together. Turn off te mixer. You might not need to use all the cream.
Lightly flour your work suface and place the dough on the surpace and pat out into a rectangle 8" x 4". Using a bench scraper to even up the edges and corners.
Cut the rectangle into 8 2" squares and then cut the squares in half diagonally. You should have 16 triangles.
Place the scones on a parchment lined baking sheet, cover with plastic wrap and freeze for 30 minutes.
After 30 minutes you can bake as many as you like, or you can store them in your freezer in a ziploc bag or airtight container and bake a a future time.
Preheat your oven to 375℉.
Place the frozen scones on a parchment lined baking sheet and brush the tops with a bit of the heavy cream.
Bake for 22-23 minutes or until golden brown. These are best served the day they are baked.