These Italian-inspired tea sandwiches are easy-to-assemble and a sure-fire crowd pleaser.
Make the pesto butter: Combine butter, basil, garlic, Parmesan, and pine nuts in the bowl of a food processor fitted with the metal blade; process until blended. Set aside. Lay prosciutto slices flat on a piece of plastic wrap, and cover with another piece of plastic wrap. Place in freezer for 10 minutes.
Remove prosciutto from freezer; use a 2 1/4-inch round cutter to cut into rounds. Slice mozzarella 1/8 inch thick, and cut into rounds. Cut bread using the same cutter, being sure to remove all the crust.
Spread a thin layer of pesto butter on two bread rounds. Layer one round with a round each of mozzarella and prosciutto; top with other bread round. Repeat with remaining ingredients. Cover with damp paper towels until ready to serve.
To make perfectly round sandwiches, cut each of the layers separately with the same biscuit cutter. Ask your butcher to slice the prosciutto more thickly than usual so it can be cut easily without tearing; you will need one round for each sandwich.