Lightly spoon flour into a measuring cup. Level off. In a bowl combine the flour and icing sugar.
Cut in butter with a fork and mix well. Press mixture into a 23cm square pan.
Bake 15 to 17 minutes until lightly brown.
To make Filling: Spread jam evenly over baked crust. In a small bowl beat cream cheese and milk until smooth. Melt white chocolate chips over low heat and add to mixture. Beat until smooth. Drop cream cheese mixture by teaspoons evenly over jam. Spread carefully and refrigerate.
To make Glaze Topping: Cut chocolate into small pieces and melt with shortening over low heat, stirring constantly. Spread over white chocolate layer. Cool completely. Cut into bars and store in refrigerator.