Preheat oven to 350°F. In a medium bowl, combine flour, 1/4 cup powdered sugar, and butter. Press mixture into 9x13 baking dish. Bake for 15 minutes or until lightly brown and then let cool.
In a mixing bowl, beat cream cheese, 3/4 cup powdered sugar, and milk. Beat until smooth. Pour over cool crust.
In a saucepan, put sugar and cornstarch. Crush strawberries and add to sugar mixture. Cook over medium heat until thickened. Remove from heat and cool. Spread over cream cheese mixture. Cover and chill.