Sugary Coca-Cola works well in this delicious dessert that's served with a shot of Coke-filled milkshake.
For the cookies:
In a medium-sized mixing bowl, cream together the sugar and butter. Add the salt, egg, Coca-Cola, and vanilla and beat until smooth. Beat in the flour and cocoa until well combined; the dough will be very stiff.
Roll the dough into balls about the size of a shelled chestnut, or a “shooter” marble (the big marble you use to shoot at the little ones. For those unfamiliar with either chestnuts or marbles, this is about 2 level teaspoons of dough.) Place the balls on parchment-lined or lightly greased cookie sheets and flatten each ball until 1/8-inch-thick, using the bottom of a glass dipped in cocoa powder. (You may also use a cookie stamp, for a more realistic faux-reo effect.) To get a nice crisp cookie, it’s important to press them thin. Use a ruler on the first one so you can see just how thin 1/8 inch is. (If you press them thinner than 1/8 inch, you run the risk of having them burn.) Place the baking sheets in the refrigerator to chill the dough for 30 minutes.
Preheat the oven to 325 degrees. Bake the cookies for 18 minutes. It’s important to bake them just the right amount of time: too little and they won’t crisp properly; too much and they’ll scorch. Watch them closely at the end of the baking time, and at the first sign of darkening edges or first whiff of scorching chocolate, remove from the oven immediately. Then, remove the cookies from the baking pans and cool them completely on a wire.
For the filling:
Soften the gelatin in a cup containing the 2 tablespoons of cold Coca-Cola, then place the cup in a larger dish of hot water and leave it there until the gelatin is completely dissolved and the liquid is transparent. Remove the gelatin from the hot water and let it cool until its room temperature but hasn’t begun to set.
In a medium-sized mixing bowl, cream the shortening, then beat in the vanilla and the confectioners’ sugar, a little at a time, beating until the mixture is light and creamy. Then, beat in the gelatin.
Sandwich the cookies, using about 1 ½ teaspoons for regular oreos, more for double-stuffed. (You’ll have some filling left over if you fill the cookies moderately.)
For the milkshake:
Combine all of the ingredients in a blender; add ice cream to desired consistency. Pour into shot glasses.