Preheat oven to 350º. Line an 8 X 8 inch baking pan with parchment paper and spray lightly with cooking spray.
With an electric mixer, cream butter until smooth, add brown sugar, flour and salt and mix until crumbly.
Place 1 ¾ cups of butter mixture into the bottom of the pan and reserve the rest for the topping.
Bake for 10 -12 minutes until slightly browned.
While the crust is baking, combine chocolate chips and sweetened condensed milk in a microwave safe bowl and microwave on medium power until chocolate has just melted. 1-2 minutes.
When crust has browned, remove from oven and pour chocolate mixture over the top.
Sprinkle remaining butter mixture over the top and place raspberries on top. If desired, pour a cup of chocolate chips over the top.
Bake for 20-30 minutes. Remove before chocolate chips melt completely.
