Red Caps

From 1922:

1 tablespoonful butter, ½ small cupful sugar, 1 small cupful flour, a pinch of salt, ½ teaspoonful of baking powder, 4 tablespoonfuls of apricot jam.
Soften the butter in a basin, add the sugar and beat well; break in eggs and beat well again; mix the flour, baking powder and salt together, and stir into the mixture. Have four large cups buttered, put a tablespoonful of jam in each, half fill the cups with the mixture; place them in a stewpan with about an inch of boiling water and steam for half an hour, turn out and serve at once.