Preheat oven to 350 degrees F (175 degrees C). Grease cookie sheets.
In a large bowl, mix together the butter, brown sugar and white sugar until smooth. Beat in the eggs one at a time, then stir in the vanilla and coffee liqueur.
Combine the flour, baking soda and salt; stir into the sugar mixture until well blended. Stir in chocolate chips. Drop dough by rounded tablespoonfuls 2 inches apart onto the prepared cookie sheets.
Bake for 10 to 12 minutes in the preheated oven, or until golden brown. Allow cookies to cool on baking sheet for 2 minutes before removing to a wire rack to cool completely.
