I've read this thread with interest, and what keeps coming to mind is the following oatmeal cake with broiled icing.Obviously you would skip the icing. But the problem is that it doesn't have buttermilk. I'm posting the recipe for the cake part anyway, because it sounds very similar in taste and texture, and the era is right:
Oatmeal Cake from Maida Heatter's "New Book of Great Desserts"
1 cup quick (not instant) rolled oats
1 1/4 cups boiling water
1 1/2 cups sifted all purpose flour
1 tsp baking soda
1 tsp cinnamon
1/4 tsp nutmeg
1/2 tsp salt
1 stick unsalted butter
1 tsp vanilla extract
1 cup granulated sugar
1 cup dark or light brown sugar, firmly packed
2 eggs
Preheat oven to 350 degrees. Butter a 9x13x2 inch metal cake pan. Dust it all over with rolled oats (in addition to those called for in the recipe), then, over a piece of paper, tap out excess. Set aside.
Place the cup of oats in a bowl, stir in the boiling water to mix, and let stand for 20 minutes.
Sift together the flour, baking soda, cinnamon, nutmeg, and salt, and set aside.
In the large bowl of an electric mixer, cream the butter. Beat in the vanilla. Add both sugars ad beat well. Then add the eggs and beat well. Beat in the rolled oats. On low speed add the sifted dry ingredients, scraping the bolw with a rubber spatula and beating only until incorporated.
Turn into the pan and smooth the top.
Bake for about 40 minutes until the cake begins to come away from the sides of the pan and until it springs back when lightly pressed with a finger tip.
I have made this cake many times and it is really wonderful.
Jo
Q