This handwritten recipe includes notes and tips for using this filling for cakes, date unknown. Recipe is typed as-is below but I did make a correction or two so the directions are a bit easier to understand. Scanned copy for archives is included as well.
Cocoa Whipped Cream Filling:
Mix:
1/2 pint heavy cream
1/2 cup confectioners’ sugar
1/4 cup dry cocoa
Few grains salt
Let stand overnight (or for several hours) in the refrigerator.
Beat until thick. Flavor with Vanilla.
This is the filling I use, it’s good with yellow cake or marble cake.
Top with any chocolate glaze or what I use is your favorite can of chocolate frosting–put it in the microwave, heat until runny consistency, pour on top of cake warm letting it run down sides of cake.
Enjoy.