In mixing bowl, cream butter, peanut butter and sugars; add egg and
vanilla.
Add dry ingredients to the creamed mixture.
Chill one hour.
Shape in 48 1" balls.
Place in miniature muffin tins.
Bake 325º
about 14-16 minutes.
(My oven bakes them in less time, so watch closely.)
Immediately they are removed from oven make a well in center of each
cookie by pressing a melon b.a.l.l.e.r in it.
Cool five minutes and
remove from pans.
Make filling by melting chocolate chips in microwave
for two minutes.
Stir in milk and vanilla.
Carefully spoon the filling into each well.
Top with nuts if desired.