Whip heavy cream and powdered sugar to soft peaks; keep chilled.
Beat mascarpone until smooth. Whisk it into the cooled custard until silky.
Fold in the whipped cream gently. Transfer filling to a piping bag with star tip.
Pipe cream into both ends of each shell. Serve soon, or chill briefly to set.
Notes
Variation: Dip the cooled shell tips in melted dark chocolate, then sprinkle with chopped pistachios or hazelnuts. For a citrus twist, add 1 tsp lemon zest to the custard. Storage: Keep empty shells airtight up to 2 days; fill shortly before serving to maintain crispness.This recipe is an original creation inspired by classic Crispy Italian Cream-Filled Cannoncini flavors. All ingredient ratios and instructions are independently developed.