1 cup + 2 tablespoons (7 and 7/8 oz) granulated sugar, plus 2 to 3 tablespoons for coating cookies
3/4 cup (1-1/2 sticks, or 6 oz) unsalted butter
1 tsp salt
1 tsp espresso powder
1 large egg
1 Tb water
1 tsp vanilla extract
1-1/2 cups all purpose flour
3/4 cup black cocoa (Hershey’s dark cocoa, plus 2 to 3 tablespoons for coating cookies)
1 tsp + heaping 1/4 tsp unflavored gelatin
2 Tb (1 oz) cold water
1/2 cup vegetable shortening
1 tsp vanilla extract
2-1/2 cups confectioners sugar
Preheat oven to 325 degrees. Lightly grease or line with parchment two or more baking sheets.
Place 2 to 3 tablespoons black cocoa and 2 to 3 table-spoons sugar in an 8- or 9-inch cake pan, shaking to distribute across bottom of pan.
To make cookies: In a medium-sized mixing bowl, beat together sugar, butter, salt and espresso powder. Beat in egg, water and vanilla, then flour and cocoa. Dough will be very stiff.
Roll dough into balls about size of a chestnut (about 2 level teaspoons). As dough balls are made, place in cake pan with cocoa. When 6 to 8 balls are in pan, shake gently to roll in cocoa and sugar, then place on prepared sheets. Repeat with all dough.
Use flat bottom of a glass, dipped in cocoa as necessary to prevent sticking, to flatten cookies to about one-eighth-thick (measure with a ruler; you want to get pretty close to one-eighth inch for best-textured cookies).
Bake cookies for 18 minutes, watching closely (it’s important to bake the right amount of time — too little, and cookies won’t be crisp; too much, and they’ll scorch). When done, remove cookies from oven and allow to cool completely on rack or on pan.
While cookies cool, make the filling: Soften gelatin in a cup with 2 tablespoons cold water, then place cup in a larger dish of hot water and leave it there, stirring occasionally, until gelatin dissolves and becomes syrupy, about 5 to 10 minutes.
Meanwhile, beat together shortening, vanilla and sugar. Mixture is very dry at first, but eventually begins to clump together. When this happens, add dissolved gelatin and beat until smooth.
Place 1 level tablespoon filling in center of one cookie; again, a teaspoon cookie scoop, slightly heaped, is perfect for this task. Place another cookie atop filling, and squeeze to distribute filling evenly. Repeat with remaining cookies. Store in an airtight container.