Cream margarine, vanilla and sugar well; beat in eggs. Sift together flour, baking powder and salt; beat in alternately with milk. Pour into a 9 inch round pan. Bake at 350 degrees for 30 minutes, or until done. Cool 10 minutes; remove from pan.
Mix sugar, flour and salt; stir in milk. Bring to boil, stirring; cook 2 minutes longer. Remove from heat. Slowly stir 1/4 cup of the hot mixture into 1 beaten egg; return to pan; heat just to boiling. Stir in margarine and vanilla. cover and chill.
Melt margarine and unsweetened chocolate. Stir in powdered sugar and boiling water until smooth. Use immediately.
Split cake into two layers; fill with cream filling and spread chocolate glaze on top. Keep refrigerated.
From: Glorious Grub Cookbook By. Joan Stewart
Madagascar Vanilla (purchase at Chefs Catalog) Of all the vanilla's I've used this is my favorite. Once you've tried it you won't go back!