Combine the cream and sugar in a heavy saucepan and bring
to a boil, cooking at a full rolling bois for 2 minutes, (A candy
thermometer will read 234 degrees F.)
Cool slightly, then beat until it just begins to thicken.
Beat in the butter and immediately spread between the layers
and on top of the cake leaving the sides unfrosted.
Decorate with the pecan halves.