Cream together butter and sugar with electric beaters.
Beat in eggs and vanilla.
Add chocolate and beat until light and creamy.
In medium bowl, mix the flour, baking powder and salt.
Mix in dry ingredients alternating with milk:1-Add about ⅓ of the dry ingredients to the chocolate mixture and mix.2-Stir in half of milk.3-Add in another third of flour mixture.4-Stir in remaining milk.5-Mix in remaining flour mixture.
Wrap with cling wrap and refrigerate for 3 hours. *Don't skip this...it makes a difference.
Preheat oven to 300° and cover baking sheets with parchment paper or silicone sheet.
Scoop a heaping teaspoon of cookie dough and roll into a ball. Roll in powdered sugar. Place about 1 inch apart on baking sheet.
Bake for 15 minutes.
Cool on cookie sheet for 5-10 minutes before removing to cooling rack.