Chop the shrimp into small, bite sized pieces. Add them to a large bowl with the softened cream cheese, mozzarella, parsley, garlic, salt, and pepper. Stir until smooth and evenly combined. The mixture should look creamy, not stiff. If needed, let the cream cheese sit at room temperature a few more minutes before mixing.

Slice the Italian bread in half lengthwise. Gently hollow out the center of each half using a spoon or your hands, leaving a sturdy shell so the bread holds the filling without tearing. Set the removed bread aside for breadcrumbs or croutons.

Spoon the shrimp mixture evenly into both bread halves. Press it down lightly so it fills every corner without overflowing. The top should be slightly mounded.

Preheat the oven to 375°F. Brush the outside of the bread generously with melted butter. Wrap each half tightly in foil, place on a baking sheet, and bake for 15 minutes until the filling is hot and beginning to melt.

Remove the foil and return the bread to the oven for another 5 minutes. The crust should turn golden and crisp, and the filling should bubble slightly at the edges.

Let the bread rest for 3 to 5 minutes before slicing. The filling will be very hot. Cut into portions with a sharp knife and serve warm.