Preheat oven to 350. Grease and flour bundt pan; set aside. Melt white chocolate in the 1/4 cup hot water in top of double boiler. When melted, set aside to cool.

In large bowl, beat shortening and sugar together well. Add eggs one at a time, beating well after each addition. Sitr in vanilla. Add melted chocolate mixture and blend on low speed to combine.

In medium bowl, sift together flour, baking powder and salt. Add to sugar mixture alternately with milk, beginning and ending with flour. Pour into prepared pan and bake about 1 hour, 15 minutes, or until tested inserted in center comes out clean. When done, cool in pan 10 minutes then invert onto wire rack to cool completely.

Icing: In medium saucepan over medium-low heat, combine margarine, evaporated milk, sugar and white chocolate. Cook stirring constantly until mixture comes to a boil. Boil 1 minute; remove from heat. Add vanilla and beat until thick. Pour over cooled cake.