In a small bowl, whisk together the flour, baking powder, and salt. Set aside.
Tip the granulated sugar and orange zest into a medium bowl, and rub them together with fingertips until the sugar is fragrant. Add the butter, and blend it into the sugar with a spatula. Stir in the egg, brandy, and vanilla. Add the flour mixture, and stir until a soft, sticky dough develops. Scoop the dough onto a sheet of plastic, and wrap it up. Chill for 2 hours or overnight. Meanwhile, line a baking sheet with plastic wrap.
Cut the dough in half, and return one half to the refrigerator. Put the first half on a lightly floured surface. Lightly sprinkle the top of the dough with more flour, and then roll it out, flipping it over frequently and adding more flour to keep it from sticking, until it is paper thin. (You can roll the dough into a neat rectangle or a free-form shape.) Use a pastry cutter, a fluted ravioli cutter, or a knife to cut the dough into strips that are approximately 1-inch-wide and 4 inches long. Roll out and cut the remaining dough into strips. Transfer the strips to the prepared baking sheet, and cover with another piece of plastic wrap. Chill for 1 hour.
Line a baking sheet with several layers of paper towels. In a heavy pot, heat 4 inches of oil to 350°F as determined by a candy thermometer. Fry 4 or 5 strips at a time just until golden brown on one side. Then flip the strips with chopsticks or a heat proof spatula, and brown the other side. Transfer to the paper towel-lined baking sheet, let drain for 1 minute, then coat both sides with confectioners' sugar. Merveilles are best when served on the day you fry them.