Combine:

1/2 c melted butter (2 sticks)
1 lb peanut butter (2 c)
4 1/2 c powdered sugar
1 t vanilla

Roll into balls and place on cookie sheets.  Freeze.  Using a toothpick dip into melted chocolate bark. ( I found it best to melt 3 chunks of chocolate, using the microwave, in a coffee cup.)

Place balls on paper-lined cabinet.  They harden quickly.  Using a spoon, drizzle warm bark over hole to cover.  You can use the same chocolate bark, or use white chocolate bark.