Chocolate Wafers Recipe

Combine the flour, cocoa, baking soda, and salt in a small bowl; whisk or fork until thoroughly mixed. Set aside.

In a separate bowl, beat the butter and margarine with an electric mixer for a few seconds, just until blended.

Add the granulated sugar, brown sugar, and vanilla to the butter mixture. Beat on high speed for about 1 minute.

Beat in the egg white until just combined.

Add the reserved flour mixture to the wet ingredients and mix on low speed until just incorporated.

Gather the dough with your hands and form it into a 9- to 10-inch log. Wrap the log tightly in wax paper or foil, twisting the ends without pinching or flattening the log itself.

Refrigerate the dough log for at least 45 minutes, or until it's firm enough to slice easily.

When ready to bake, preheat the oven to 350°F. Position racks in the upper and lower thirds of the oven. With a sharp knife, cut the chilled dough log into slices a scant 1/4-inch thick.

Place the sliced dough 1 inch apart on cookie sheets. Bake for 12 to 14 minutes, or until the cookies puff and crackle on top, then begin to settle slightly. Rotate the baking sheets from top to bottom and front to back about halfway through the baking time for even cooking.

Slide the parchment or foil with the cookies onto cooling racks and let them cool completely before storing or stacking.