Combine the milk and half of the sugar in a large saucepan over medium heat, whisking constantly as the milk begins to warm.
In a separate bowl, whisk together all of the eggs with the other half of the sugar. Once combined, whisk in the cornstarch.
Pour a portion of the heated milk into the bowl with the eggs, "tempering" the hot into the cold. Return all of the combined egg/milk mixture to the saucepan with the rest of the milk. Whisk constantly and quickly until the mixture thickens to a thinned-out yogurt consistency.
Increase the heat and using a wooden spoon, continue stirring the cream to get out any leftover cornstarch flavor.
Remove the cream from the heat and stir in the butter and vanilla.
Squeeze out the soaked gelatin sheets and stir them into the cream.
Transfer the cream to the bowl of a mixmaster and beat it with a paddle attachment on the lowest speed until it has completely cooled (Note: this can take up to 15 minutes).
Whip the heavy cream until it forms medium peaks.
Fold the whipped cream into the completely cooled pastry cream and use within 3 days.
★ Did you make this recipe? Don't forget to give it a star rating below!