Preheat oven to 350 degrees. In a small, heavy-bottomed pan, melt chocolate and shortening, stirring over low heat until smooth and melted. Remove from heat and stir in vanilla. In large bowl, combine flour, sugar, baking powder, baking soda and salt. Add chocolate mixture, milk and eggs, beating until smooth. Spread mixture in two greased and floured 23 cm round cake pans.
Bake for 30 to 35 minutes or until toothpick inserted in center of cake comes out clean. Cool in pans 5 minutes before turning out onto wire rack.