- Put together water, coffee, sugar and vanilla extract in a small bowl, stir for a while then set aside.
- Mix coffee mixture and ice cream in a large bowl, stir gently until liquid is blended into the ice cream.
- Spoon the mixture into pie crust, smooth top with a rubber spatula.
- Cover it with plastic wrap and put it in refrigerator for about 4 hours or until firm.
- Cut into 8 slices and serve.