Spread the butter on the bread slices. Turn over and spread the other side of one slice with the cream cheese.
Heat a skillet and place the cream cheese slice butter-side-down in the pan. Layer the prosciutto, tomato, basil and provolone on top of the cream cheese. Top with a 2nd slice of bread, butter-side-up.
Cover, and heat the sandwich on low until lightly browned. Carefully flip and toast the other side.
Remove to a cutting board. Let sit for a couple of minutes, then cut with a serrated knife and serve immediately.