Preheat the oven to 325 degrees.
Line your 8x8 pan with nonstick foil.
Melt the butter and unsweetened chocolate together over low heat in a medium saucepan stirring.
Remove from heat and add the sugar. Mix well.
Add eggs and vanilla.
Add chocolate chips, flour, vanilla & salt.
Pour in the pan and bake 35-40 minutes.
Remove and cool on a rack.
Cut into squares.