1½ (14.1-ounce) packages refrigerated pie dough (3 sheets)
3 tablespoons salted butter
1 cup firmly packed dark brown sugar
¼ cup all-purpose flour
¼ teaspoon fine sea salt
2 cups whole milk
4 large eggs, separated, at room temperature
½ teaspoon vanilla extract
2 tablespoons granulated sugar
¼ teaspoon cream of tartar
Instructions
Preheat oven to 450°.
Spray 27 (2¼-inch) tartlet pans with cooking spray. Set aside.
On a lightly floured surface, unroll pie dough. Using a 2¾-inch round cutter, cut 27 rounds from pie dough. Press dough rounds into prepared tartlet pans, trimming edges as necessary. To prevent puffing during baking, prick bottoms of dough with a fork. Place tartlet pans on rimmed baking sheets. Refrigerate for 30 minutes.
Bake until light golden brown, approximately 5 to 7 minutes. Let cool completely on baking sheets.
Gently remove tartlet shells from pans, and place shells in the wells of mini muffin pans. (This will keep tartlet shells upright for filling and for baking meringues.) Set aside.
Reduce oven temperature to 350°.
In a medium saucepan, melt butter over low heat. Add brown sugar, flour, and salt, stirring to combine.
In another saucepan, scald milk.
In a small heatproof bowl, beat egg yolks with a whisk until light-colored. Temper egg yolks by gradually adding ½ cup scalded milk, stirring constantly. Add remainder of milk, stirring well. Slowly add egg yolk mixture to brown sugar mixture, stirring constantly. Cook, stirring constantly, over medium heat until mixture thickens and coats the back of a spoon, 3 to 4 minutes. Remove from heat, and add vanilla extract, stirring to blend. Let mixture cool slightly, stirring occasionally.
Divide pudding among baked tartlet shells. Set aside.
In a medium bowl, combine egg whites, sugar, and cream of tartar. Beat at high speed with a mixer until stiff peaks form. Transfer meringue mixture to a piping bag fitted with a large open-star tip (Wilton #1M). Pipe a meringue star onto each tartlet.
Bake until meringue is light golden brown, 3 to 4 minutes. Let cool completely.
Refrigerate, lightly covered, until cold, approximately 4 hours.