Sprinkle the unflavored gelatin over the cold water in a small bowl and let it sit for 5 to 10 minutes.

In a medium saucepan, combine the whole milk with 1/4 cup of granulated sugar. Scrape the seeds from the split vanilla bean and add both the seeds and pod into the milk. Heat until steaming (about 5–7 minutes).

Whisk together the remaining 1/4 cup sugar and egg yolks in a separate bowl until pale. Gradually pour about half of the hot milk into the yolks while whisking continuously.

Return the yolk mixture to the saucepan and cook over medium-low heat, stirring constantly for about 4 to 5 minutes until thickened.

Remove from heat and strain through a fine mesh sieve. Stir in the bloomed gelatin until fully dissolved.

Cool the custard to room temperature while stirring occasionally.

Whip the heavy cream to soft peaks and gently fold into the cooled custard in two additions.

Transfer the mixture to your desired mold and refrigerate for at least 4 hours until set.