Preheat oven to 350.

Combine flour and salt in bowl. Beat butter & sugar until light & fluffy. Beat in egg. At low speed, beat in flour mixture. Refrigerate dough 30 minutes.

Shape dough into sixty 3/4 inch balls. Transfer to ungreased cookie sheets. Flatten each ball to 1 1/2 inch circles. Bake 13 to 15 minutes, until light golden.

Filling: Beat butter, sugar & rum in bowl until smooth. Spread evenly on flat side of half the cookies. Top with remaining cookies to make sandwiches. Refrigerate 30 minutes.

To frost: Microwave chocolate on high for 1 1/2 to 2 minutes, stirring after 1 minute, until melted. Spread top of each cookie with chocolate, then dip in chopped pistachio nuts. Refrigerate until set, about 10 minutes.

Makes 30 cookies.

My Notes: I found that the thinner I pressed out the cookie, the nicer texture the finished product had. The amount of chocolate was very adequate, and dont' make it too thick because it then contrasts a bit with the texture of the cookie itself which is very delicate. The filling amount was adequate, but I prefer to make 1/2 recipe more and add some extra confectioner's sugar because at room temperature it's a bit soft. However, the nuts were not enough...I found I used a whole cup of pistachios.