Pre-heat oven to 375°F. Spray mini muffin tray with non-stick cooking spray; set aside.
Slice prociutto in half lenghtwise to make 24 long, thin strips.
Take one strip of prosciutto and place across an empty muffin cup, with the middle of the strip over the mid-point of the cup. Press the center of the prosciutto strip into the bottom of the cup. Carefully fold and wrap one end of the prosciutto around one interior side of the cup until it overlaps the prosciutto on the opposite side. Repeat with the opposite side of the prosciutto so that the exposed areas of the muffin cup are covered to form a “basket.” Repeat process with remaining 23 muffin cups.
Bake for 9-10 minutes. Closely watch while "baskets" bake so they don’t overcook. The edges of the prosciutto will start to brown when ready.
While baking, combine the goat cheese, ricotta cheese, heavy cream, and thyme leaves in a medium bowl. Season with salt & black pepper, to taste, and stir to combine. Set aside.
Remove the muffin tray from the oven and cool for several minutes before transferring each prosciutto basket to a plate lined with paper towels.
Flip each basket after a few minutes and blot carefully to remove excess grease. When complete, transfer prosciutto cups to serving platter.
Transfer the cheese mixture to a pastry bag fitted with a tip. Carefully pipe the goat cheese mixture into each prosciutto cup.
If desired, top each cup with chopped pistachios and serve.