In a medium bowl, cream together the butter and brown sugar until light and fluffy.
Add the vanilla extract, salt and baking soda, mix until combined.
Stir in the flour and mix until a soft dough forms.
Stir in the chocolate chips.
Drop spoonfuls of dough onto a parchment lined baking sheet.
Bake for 10 minutes at 350°F. Allow to cool before using.
To assemble the sandwiches: Place a scoop of ice cream between two cookies. Press gently to adhere them together. Wrap each sandwich in parchment paper and freeze until hard.