Combine milk and cream in medium saucepan. Whisk in combined sugar, dextrose, milk powder and ice cream stabilizer. Cook on medium heat, stirring occasionally, until mixture reaches 165°F. Stir in 3 oz. cookie pieces. Let stand at room temperature 30 min. Strain into bowl; discard solids.
Blend milk mixture, in small batches, in blender 30 seconds. Pour into medium bowl. Chill bowl over ice water bath until mixture is cold. Stir in vanilla. Refrigerate overnight.
Freeze mixture in ice cream maker according to manufacturer's directions. When firm, stir in 4.5 oz. cookie pieces. Layer half the ice cream with half the fudge topping in clean container. Swirl chocolate into ice cream before adding another layer of each. Freeze until very firm.
For each serving: Portion 3 scoops (#30) ice cream in a dessert glass. Garnish with 1/4 oz. of the remaining cookie pieces.