Combine dates and water in a pan over medium heat. Cook until dates are soft and water is absorbed. Set aside and let cool.
In a small bowl, mix together flour, baking powder and salt.
Preheat oven to 350°F (180°C).
In a large bowl, using an electric mixer, beat together granulated and brown sugars and butter until well combined. Add eggs, one at a time, beating well after each addition.
Add flour mixture and crushed unibic cookies, beating until combined. Add milk and reserved date mixture, beating until smooth.
Scoop batter into prepared pan. Bake in preheated oven for 20 to 25 minutes or until golden brown and tops of cupcakes spring back when lightly touched. Let cool in pan on rack for 10 minutes.