Melt chocolate in saucepan over low heat.

Add sugar and milk and stir until it boils.

Cook without stirring until reaches 235 degrees (forms a soft ball when dropped in water).

Remove from heat, add butter and let sit in a pan of cold water until cool.

Add vanilla and beat until creamy.

Pour into buttered pan and mark into squares.

(4 tbsp of cocoa may be substituted for the chocolate)