For the cake, melt chocolate in a small water bath, you could use about 1/2 cup for the water bath. Be sure that the water does not boil. Add butter and stir until butter is melted and the mixture is smooth. Remove from heat and set aside.
Sift together: flour, baking soda, and salt. In a large bowl, beat eggs and vanilla until foamy. Add sugar gradually and continue beating until mixture is thick and lemon-colored and eggs hold a crease, this will take about 5 minutes. Gradually fold in flour mixture alternately with chocolate mixture, mixing after each addition until ingredients are well incorporated.
Pour batter into three nine-inch cake pans, which have been buttered and floured. Bake at 350 degrees for 25 minutes, or until done. Allow to cool, and loosen cakes from pans. When completely cool remove from pans and place on a wire rack. Spread 1/2 jar of preserves over one cake layer, and then place the second layer on top. Spread remaining jam over the cake. Top with a third later. And cover the top and sides of the cake with the chocolate glaze.
Glaze Instructions
To make the chocolate glaze, heat the chocolate chips and evaporated milk in a saucepan over moderate heat, take care not to scorch the chocolate. You may need to add a little milk if this is too thick.