-
Preheat the
oven to 375°F/190°C/gas 5. Butter two cookie
sheets. Sift the flour and cocoa into a medium
bowl.
-
Beat the
butter and sugar in a large bowl with an
electric mixer at medium speed until creamy. Add
the egg yolk, beating until just blended.
-
Mix in the
dry ingredients. Form the dough into three equal
size disks, wrap in plastic wrap, and
refrigerate for 30 minutes.
-
Roll out the
dough on a lightly floured surface to a
thickness of 1/4 inch (5 mm).
-
Use a 2inch
(5-cm) cutter to cut out twenty circles and use
a 1 1/2inch (4-cm) cutter to cut out another
twenty circles, re-rolling the dough as
necessary.
-
Place one of
the larger circles on a cookie sheet. Place a
piece of chocolate in the center. Cover with one
of the smaller circles.
-
Working
carefully, mold the smaller circle over the
chocolate and turn the edges of the larger
circle upward.
-
Press around
the edges with a fork to seal the chocolate
completely. Repeat with the rest of the circles,
spacing 2 inches (5 cm) apart.
-
Bake for
8-10
minutes, or until the cookies have spread
slightly. Cool on the sheet for 5 minutes.
Transfer to racks to cool.