Preheat oven to 375 degrees Fahrenheit.

Slice crusty Italian bread into 1/4 inch rounds on a diagonal.

Lightly coat the bread slices with extra virgin olive oil.

Zest the entire lemon and juice half of it.

In a bowl, combine the ricotta cheese, diced fresh rosemary, shredded parmesan cheese, lemon zest, and lemon juice.

Season the ricotta mixture with salt and pepper to taste.

Spoon the ricotta mixture onto each bread slice.

Cut the prosciutto slices in half.

Place a piece of prosciutto on top of the ricotta mixture on each crostini.

Slice the Roma tomatoes into small rounds.

Place one slice of tomato on top of the prosciutto on each crostini.

Bake in the preheated oven for 15-20 minutes, or until the bread is golden brown and the ricotta mixture is set.

Right before serving, garnish with freshly cut basil leaves.

Lightly drizzle with extra virgin olive oil and balsamic vinegar.