Rolled, fried pastry tubes filled with meringue are a delicate Mexican confection from Puebla. This light, crispy dessert is a family favorite that showcases the artistry of Mexican pastry.
In a large bowl, combine the flour, salt, melted butter, and egg yolks. Gradually add the milk, kneading until a smooth dough forms.
Wrap the dough and let it rest for 20 minutes at room temperature to relax the gluten.
On a lightly floured surface, roll the dough out very thin, about 1/16-inch. Cut into 3x4-inch rectangles and roll each around a metal cannoli tube or similar mold.
Heat vegetable oil to 350°F in a deep skillet. Fry the dough-wrapped tubes in batches until golden and crisp, about 2 minutes, turning for even color. Drain on paper towels and cool completely before carefully sliding out the tubes.
To make the meringue, beat egg whites on medium speed until soft peaks form. Gradually add granulated sugar and vanilla; continue to beat until stiff, glossy peaks form.
Fill a piping bag with the meringue and pipe into each pastry tube. Dust with powdered sugar just before serving.