Cookie Base
1/2 cup confectioners' sugar
1/3 cup blanched sliced almonds
1 cup unsalted butter
1/2 teaspoon pure almond extract
2 teaspoons light rum
1 2/3 cups all-purpose flour
1/4 teaspoon salt

Soften the butter. Grate the almonds finely. In a medium bowl, whisk together the flour, grated nuts, and salt.

In a mixing bowl, cream the sugar and butter until light and fluffy. Beat in the almond extract and rum until well blended. Scrape the sides of the bowl. On low speed, beat in the flour mixture until incorporated. Scrape the dough into a bowl and refrigerate it for at least 2 hours or overnight.

Working with a small amount of the dough at a time, briefly knead it until it is malleable but still well chilled, and roll it on the floured cloth to a 1/8-inch thickness. Cut out the cookies, using a small metal spatula to transfer them to the cookie sheets, 1 inch apart. Re-roll the scraps, chilling the dough as necessary. For a decorative effect, if desired, use the pastry tube to cut out 1/2-inch holes in the center of half the cookies. The cookies with holes in the center will serve as the top portions of the sandwich cookies.

Bake for 8 to 10 minutes at 375 degrees F, or until just beginning to become golden. Use a small, angled metal spatula or pancake turner to transfer the cookies to wire racks to cool completely.

Butter Rum Cream Filling
3 tablespoons unsalted butter
1 cup confectioners' sugar
3/4 teaspoon light rum
2 teaspoons heavy cream

Soften the butter. In a mixing bowl, with the mixer at low speed, cream the butter and sugar until well mixed. Still at low speed, beat in the rum and heavy cream.

To fill the cookies, use a small metal spatula to spread a rounded 1/2 measuring teaspoon of the butter cream on the underside of 1 of the whole cookie bottoms. Place a second cookie (if desired, one with a hole in it), bottom side against the butter cream, and press the 2 cookies together.