1Heat oven to 350°F. In large bowl, stir cookie base ingredients until soft dough forms. Spread in ungreased 13x9-inch pan. Bake 15 to 18 minutes or until light golden brown.
2Meanwhile, in large bowl, beat almond paste, sugar and 1/4 cup melted butter with electric mixer on low speed until blended. Add 2 eggs; beat until well blended (mixture may be slightly lumpy).
3Spread almond paste mixture over partially baked base. Sprinkle with 1/2 cup almonds. Bake 15 to 20 minutes longer or until filling is set (filling will puff up during baking). Cool completely, about 1 hour.
4In 1-quart heavy saucepan, melt white chocolate and shortening over low heat, stirring constantly, until smooth. Pour and spread over cooled bars. Sprinkle with 1/4 cup almonds. Let stand about 30 minutes or until topping is set. For bars, cut into 8 rows by 4 rows. Store covered at room temperature.