Blend 2 cups of blackberries until smooth. Strain through a fine mesh sieve to remove seeds, then transfer to a saucepan. Add ½ cup sugar, 2 tablespoons cornstarch, and 1 tablespoon lemon juice. Cook over medium heat for about 5 minutes until thickened. Stir in 1 tablespoon of bloomed gelatin.

Pour the blackberry mixture into a bowl. Cover tightly with plastic wrap and refrigerate for at least 6 hours.

In a saucepan, heat 1 ½ cups of milk with a vanilla bean and 2 Earl Grey tea bags over medium heat. Steep for about 15 minutes. In a bowl, whisk together 4 egg yolks and ½ cup sugar until pale. Gradually whisk in the warm milk mixture, then return to the saucepan. Cook over low heat for about 10 minutes until thickened. Chill.

Combine 2 cups flour, ¼ cup sugar, and ½ teaspoon kosher salt in a food processor. Add ½ cup cold butter, pulsing until the mixture resembles coarse crumbs. Incorporate 1 egg yolk and 2-3 tablespoons cold water. Wrap in plastic wrap and chill for 1 hour.

Preheat oven to 350°F (175°C). Roll out chilled dough to ¼ inch thickness and press into tart pans. Prick the bottom with a fork and bake for 20-25 minutes until golden brown. Cool completely.

Whip 1 cup of heavy cream until soft peaks form, then fold gently into chilled pastry cream. Layer blackberry filling into each tart shell, top with pastry cream.

Garnish with fresh blackberries and refrigerate for at least 30 minutes to set before serving.