Root Beer Pudding

In a commercial blender, grind 1/2 cup root beer candies, the milk powder, cornstarch, and salt into a powder.
In a medium saucepan over moderate heat, bring the whole milk and root beer soda to a simmer. Carefully add the hot mixture to the powder in the blender, and with the blender on low, process for 1 minute. Add the butter and egg yolks, then gradually increase the blender speed to high and blend until smooth, about 1 minute.
Carefully pour the hot pudding back into the medium saucepan, place over moderate heat, and cook, whisking vigorously, until it comes to a simmer. Continue cooking, whisking constantly, until the pudding is very thick, about 2 more minutes. Remove from the heat and let cool to room temperature, about 30 minutes. Place plastic wrap directly on the surface of the pudding and refrigerate at least 1 hour. DO AHEAD: The pudding can be prepared ahead and kept, covered in the refrigerator, up to 2 days.
Spray a heatproof rubber spatula with nonstick vegetable oil spray and have ready. Line a large rimmed baking sheet with a nonstick baking mat or spray with nonstick vegetable oil spray.
In a medium saucepan over high heat, bring the sugar, glucose syrup, and water to a simmer. Cook, swirling the pan occasionally but not stirring, until the mixture turns a medium-dark caramel color, about 5 minutes. Add the butter, cashews, and salt and use the sprayed rubber spatula to stir the mixture until the cashews are completely covered in caramel.
Carefully pour the nougatine onto the prepared baking sheet, and use the rubber spatula to spread it into a thin, even layer. Set aside to cool and harden, about 30 minutes. Once the nougatine is completely cool, use your hands to break it into small pieces then transfer to a Robot Coupe or food processor, and grind into a coarse powder. DO AHEAD: Nougatine can be made ahead and kept, in an airtight container at room temperature, for 1 week.
In the bowl of a stand mixer fitted with the whisk attachment, beat the cream and sugar until medium peaks form.
Place the remaining 1/2 cup root beer candies in a resealable plastic bag and use a meat mallet or rolling pin to crush them into small pieces.
Divide the chilled pudding among 4 chilled glasses. Dollop each pudding with whipped cream and garnish with the crushed cashew nougatine and root beer candy pieces.