Roast bael on sheet tray in 200°C oven for about 20–30 minutes to deep golden brown.

Combine cream with chestnuts, roasted bael, and sugar in saucepan, place over medium heat and cook for about 2 hours, stirring regularly as needed (cream will break during cooking process).

Pass cream through fine mesh strainer into blender, add salt, discard chestnuts and bael, blend on high speed until very smooth.

Transfer to storage containers and reserve in ice bath or blast chiller until cool, then transfer to cooler.