Preheat oven to 325 degrees

Line 2 cookie sheets with Silpats.

Roughly chop chocolates and place them in the top of a double boiler over warm water.  Melt chocolates, stirring occasionally.  Set aside once melted.

Sift together the flour, cocoa, baking soda and salt.  Set aside.

In the large bowl of a mixer, beat the butter until softened.  Add the vanilla and sugar and beat well.  Beat in eggs, one at a time.

Add the melted chocolate and beat to mix.

On low speed, add the dry ingredients slowly.  Beat to mix.  Remove the bowl from the mixer.

Mix in the chopped mints and stir deeply to the bottom of the bowl to be sure that everything is well mixed.

Use a rounded tablespoon of the dough for each cookie.  Place the mounds about 2 inches apart on your cookie sheets.  You should only get 6 per sheet. 

Bake two cookie sheets at a time for 18 minutes.  Reverse the sheets top to bottom and front to back during baking to insure even baking.

With a wide spatula, transfer the cookies to racks to cool.