Preheat oven to 375°.
Pulse biscotti in food processor 10 times or until crumbly. Add butter through food chute; pulse 5 times or just until crumbs are moist. Set aside 2 teaspoons crumb mixture. Press remaining crumb mixture into a 9-inch pie plate.
Bake at 375° for 8 minutes or until edges begin to brown. Cool on a wire rack.
Stir together sugar, cornstarch, and salt in a medium saucepan; add milk. Bring to a boil over medium-high heat and cook 1 minute, stirring constantly with a whisk. Remove from heat. Gradually stir about one-fourth of hot mixture into egg; add mixture into remaining hot mixture, stirring constantly. Cook over low heat 3 minutes. Remove from heat; stir in lemonade concentrate and butter. Place pan in a large bowl of ice water. Cool pudding to room temperature (about 5 minutes), stirring often with a whisk.
Pour pudding into prepared crust. Press plastic wrap over filling. Chill 8 hours or until thoroughly chilled.
Before serving, spread whipped topping over filling. Sprinkle reserved crumbs over topping and garnish with raspberries.