Step #1 Place the chocolate in the top of a small double boiler over hot water on moderate heat.
Step #2 Cover until partially melted, then uncover & stir until smooth.
Step #3 remove this from the heat & set aside to cool slightly.
Step #4 Sift together the flour, baking soda, baking powder, & salt & set aside.
Step #5 In the large bowl of an electric mixer cream the butter.
Step #6 Add the vanilla & sugar & beat to mix well.
Step #7 Add the melted chocolate and beat until incorporated.
Step #8 Then add the light cream or milk & the egg & beat to mix well.
Step #9 On low spead add the sifted dry ingredients, scraping the bowl with a rubber spatula & beating only until incorporated.
Step #10 Place the dough on a piece of wax paper, fold the sides of the paper over the dough & press down on the paper to flatten the dough to a scant 1-inch thickness, wrap in the paper & put in the fridge for 20 to 30 mins -- no longer or the dough will crack when you roll it out.
Step #11 (However, if you do put in the fridge it for longer -- even overnight -- let it stand at about room temp for about an hr before rolling it out.
Step #12 ) Adjust two racks to divide oven into thirds & preheat your trusty oven to 400 degrees.
Step #13 Line cookie sheets with aluminum foil.
Step #14 Flour a pastry cloth & place the dough on it.
Step #15 (If you have doubled the recipe, roll only half of the dough at a time.
Step #16 ) With a floured rolling pin -- which should be refloured frequently to avoid sticking ~- roll the dough out until it is only 1/8-inch thick (thin).
Step #17 I use a round cookie cutter that is 2 3/4 inches in diameter -- use any size you like, & cut the cookies as close to each other as possible.
Step #18 Place the cookies 1/2 inch apart on the aluminum foil.
Step #19 (It might be necessary to transfer the cookies from the pastry cloth to the foil with a wide metal spatula -- handle them carefully in order to keep them perfectly round & flat.
Step #20 ) Leftover pieces of the dough should be pressed together & rerolled.
Step #21 Bake two sheets at a time for 7 to 8 mins, reversing the sheets top to bottom & front to back once to insure even taking.
Step #22 Bake until the cookies feel almost firm to the touch.
Step #23 These are supposed to be crisp (they will become more crisp as they cool) & they should not be underbaked, but watch them carefully to be sure they do not burn.
Step #24 (If you bake one sheet at a time, bake it on the upper rack.
Step #25 ) With a wide metal spatula, transfer the cookies to racks to cool.
Step #26 Store airtight.
Step #27 Makes 36 2 3/4 inch cookies.
Step #28 Wonderful thin, plain cookies, crisp, the dough is rolled out & cut with a cookie cutter.
Step #29 The recipe can easily be doubled if you wish.