Yield: makes eight 4-inch tarts
Sweet Tart Dough: Beat butter with a paddle until smooth. Add sugar and continue to beat until light in color.
Mix together eggs and vanilla paste. Gradually add it to the butter while mixing at medium speed.
Reduce speed to low and add flour and salt. Mix until the dough just begins to clump together
Dump dough onto lightly floured table and knead until dough becomes smooth. Divide dough in half. Form into 2 squares 1 inch thick and wrap in plastic. Chill dough for 30 minutes to 1 hour.
Roll dough out to 1/8'' thick and line tartlet shells. Dock the dough and freeze for 15 minutes.
Remove from freezer and cover shells with parchment paper and fill with weights. Bake in a preheated 350 degrees F oven for 15 minutes. Removes the weights and bake for another 5 minutes until tart shell is golden brown.
Pistachio Pastry Cream: Instructions found on King Arthur's Flour website.
Caramelized Pistachios: Heat sugar and water in a saucepan. Swirl liquid around until sugar is fully dissolved, but do not stir.
Microwave pistachios for 10 seconds.
Once sugar syrup reaches a nice amber color, add the warmed pistachios to the saucepan. Coat the nuts in the syrup and pour onto a parchment lined sheet pan. Spread the nuts, breaking any clumps that have formed. Let the nuts cool.