Put the cream cheese and heavy cream in a small mixing bowl and blend with a rubber spatula until smooth. Fold in the dill, lemon zest, salt and pepper until evenly combined.
Using a butter knife or offset spatula, spread the dill cream cheese on 1 side of each pumpernickel slice. Put a slice of smoked salmon on 12 of the pumpernickel slices. Top each sandwich with remaining bread. Arrange on a serving platter and serve immediately.
Copyright 2009, Television Food Network, G.P., All Rights Reserved