Step 1: Make the Meringue
Preheat oven to 225°F (110°C) and line a baking sheet with parchment paper.
Beat egg whites until foamy; add cream of tartar if using.
Gradually add granulated sugar while beating to stiff, glossy peaks.
Gently fold in powdered sugar.
Pipe or spoon into 6-8 2.5-inch rounds.
Bake for 90–120 minutes until dry. Cool completely.
Step 2: Make Chestnut Purée
Combine chestnuts, sugar, and milk in a saucepan. Simmer for 10–15 minutes.
Stir in vanilla and rum (if using).
Blend until smooth; thin with milk if necessary.
Push through a sieve for extra smoothness.
Step 3: Whip the Cream
Beat cream, powdered sugar, and vanilla to soft peaks.
Chill until ready to assemble.
Step 4: Assemble the Dessert
Place meringues on plates.
Add a dollop of whipped cream.
Pipe chestnut purée in thin strands over the cream.
Dust with powdered sugar.