Fill each mold cavity less than 1/2 full with melted candy. Using a decorator brush, paint the coating onto the sides of each mold to the top edge. Coat mold so that no light can be seen through the shell. Place mold in refrigerator for a few minutes to harden candy shell.
Fill each shell with Truffle or Peanut Butter filling. Roll the filling mixture into a log and then cut into pieces to fill each mold cavity. Press lightly to conform to cavity shape. Keep filling below top edge of mold about 1/8 in., to leave space to seal with melted candy.
Add additional melted candy to seal top. Tap lightly. Refrigerate until firm and completely chilled. To remove, gently tap mold on table to release. If candy doesn't release, place back in refrigerator and chill again. When completely chilled the mold itself should look frosty than clear.