Strawberry Tartlets With Breton Shortbread Crust

Name: Strawberry Tartlets With Breton Shortbread Crust
Ingredients: 1 large organic egg; 3 tablespoons unrefined blond cane sugar (also sold as evaporated cane juice); 2 tablespoons cornstarch; 2/3 cup/160 ml milk (not skim) or unflavored, unsweetened nondairy milk; Grated zest of 1 organic lemon; 1/4 cup/60 ml freshly squeezed lemon juice; 1 1/4 pound/560 grams strawberries, preferably small, hulled and halved or quartered depending on their size; 2 tablespoons strawberry jam (optional); 1/3 cup/70 grams unrefined blond cane sugar (also sold as evaporated cane juice); 6 tablespoons/85 grams high-quality unsalted butter, softened; 1 small fresh vanilla bean or 2 teaspoons pure vanilla extract; 1 cup/130 grams all-purpose flour; 1 teaspoon baking powder; 1/2 teaspoon fine sea salt