Heat heavy cream, milk, 6 tablespoons sugar, salt, and vanilla bean with half of the seeds in a medium saucepan over medium heat. Bring to a gentle simmer, stirring occasionally. Remove from heat as necessary if it starts to boil.

In a mixing bowl, whisk together egg yolks and 2 tablespoons sugar until well blended. Add cornstarch and mix until very well combined and fluffy.

Take about ½ cup hot cream mixture and slowly pour hot cream mixture while vigorously whisking into the egg yolk mixture. Replace back on heat and reduce temp to medium-low. Whisk the remaining cream mixture and slowly pour in the egg yolk mixture.

Cook mixture, whisking constantly until thickened. Allow it to boil for about 30 seconds after it has started to cook out the starchy flavor.

Immediately force mixture through a fine mesh strainer into a bowl. Mix in 1 tablespoon of butter. Cover with plastic wrap pressing directly against surface of custard. Chill thoroughly, about 2 hours.

Preheat oven to 350 degrees. In a mixing bowl, whisk together flour, baking powder, and salt for seconds, set aside.

In the bowl of an electric stand mixer fitted with the paddle attachment whip butter and granulated sugar until pale and fluffy.

Mix in egg then blend in egg whites and vanilla. Add ½ of the flour mixture and blend just until combined, then add milk and blend just until combined and finish adding in remaining ½ flour mixture and blend just until combined.

Divide batter among 12 paper-lined muffin cups, filling each cup about ⅔ full.

Bake in preheated oven 21 - 24 minutes until toothpick inserted into center of cupcake comes out clean. Transfer to a wire rack to cool completely.

Pipe or spread chilled pastry cream over cooled cupcakes into an even layer. Sprinkle entirety of pastry cream with sugar then heat with a kitchen torch until sugar begins to melt and caramelize.

Coat the edges of pastry cream while rotating the cupcake, then sprinkle tops. Torch it and add another layer of sugar, if desired.

Garnish with whipped cream and a blackberry or raspberry if desired. Serve immediately or refrigerate for 30 – 60 minutes before serving.