Turns out the cake part was coffee cake with cranberries in it, but here is the Brandy Sauce:
1/2 c butter
1 c sugar
2 Tbsp water
1 egg, beaten
2 Tbsp lemon juice
1/2 tsp grated lemon rind
1/4 c apricot brandy
Dash of salt
Cream butter and sugar thoroughly until light and fluffy in the top of the double boiler. Add water and egg and beat well. Place over boiling water for about 15 minutes or until sugar is thoroughly melted and sauce is slightly thickened, stirring often to keep smooth. Add lemon juice and rind, brandy and salt. Continue cooking for 5 minutes, stirring to blend. Serve warm.
This comes from Meta Given's "Modern Encyclopedia of Cooking" from 1955 - the eighteenth printing. It was originally copyrighted in 1947. The old stuff is still good!