Beat together the cream cheese and ricotta. Divide the filling among 4 slices of bread, spreading to the edges. Spread a thin layer of preserves or marmalade over the cheese. Top with another slice of bread. (May be frozen at this point.)
Preheat the griddle to 375. Whisk together the eggs and heavy cream in a shallow pan or dish in which you can dip the sandwiches. Dip both sides of each sandwich in the egg mixture. Put a pat of butter on the griddle for each sandwich and sauté sandwiches until golden brown on each side, turning once.