1Heat oven to 350°F. Spray 9-inch square pan with cooking spray (without flour).
2In large bowl, stir cookie mix, oats, butter, egg and vanilla until crumbly. Press half of the mixture in pan. Reserve remaining crumb mixture for topping. Bake 10 minutes.
3Meanwhile, in medium microwavable bowl, microwave caramels and milk uncovered on High 3 minutes, stirring after each minute, until caramels are melted. Stir until smooth. Pour over partially baked crust. Sprinkle with reserved crumb mixture; pat lightly.
4Bake 15 to 18 minutes or until light golden brown. Cool completely in pan on cooling rack, about 1 hour. Cut into 5 rows by 4 rows.