Preparation / Directions:
Grind almonds in a blender until they resemble large bread crumbs; set aside. In the large bowl of an electric mixer, cream butter until it is very smooth and creamy. Slowly add the confectioners' sugar and beat until the mixture is very smooth. Beat in the zest and liqueur. In a small bowl, combine the flour, salt, and ground almonds. Stir the flour mixture until very well combined. Chill the mixture for least 3 hours or overnight.
Preheat the oven to 375 degrees. Butter two cookie sheets. Measure out the cookie dough into 1/2 tablespoon increments. Roll each spoonful of dough into a ball and place them, two inches apart on the cookie sheet. Butter the bottom of a glass, then dip the glass bottom in sugar. Flatten each cookie with the buttered and sugared glass bottom to a diameter of 2 1/4 inches. (Do not make the cookies too thin.) Dip the glass into the sugar before flattening each cookie. Bake approximately 7 to 10 minutes or until the cookies are just cooked through but not at all browned. After removing the cookies form the oven, allow them to cool 1 minute on the cookie sheets. Then transfer them to racks to cool completely.
For the filling: in the large bowl of an electric mixer, beat the butter until smooth. Add the sugar, cream and liqueur, and beat until very smooth and creamy. Spread about a teaspoon of filling on the flat underside of half the cookies ; make a sandwich with the flat underside of the other half of the cookies. Store tightly covered.
Makes 64 sandwich cookie