Whisk the egg yolks and ¼ cup of the spruce syrup over a double boiler until doubled in volume, then reserve. Combine the whites with the 2 tablespoons of syrup and whisk in a double boiler until soft peaks form, then remove from the heat and whisk to full volume by hand.
In a separate bowl, whip the cream to soft peaks and reserve.
Melt the chocolate and butter in a double boiler, then mix with the egg yolk mixture.
Fold ¼ of the beaten egg whites into the egg yolk-chocolate mixture until combined, then mix in the rest.
Finally, gently fold in the cream until just incorporated.
Put the mixture into a piping bag with a fluted tip, then pipe into dishes and chill until ready to serve. It can also be scooped with a disher or scoon dipped in hot water.
Notes
Yield: roughly 4 cups, enough to serve 8-10 people a small scoop. This is rich stuff.