1) Using an electric mixer, beat the butter or vegetable fat and sugar in a large bowl until fluffy. Beat in the egg and the brandy. Beat in the salt. Add the flour and beat until blended.
2) Transfer the dough to a lightly floured work surface and knead until a soft dough forms. Form the dough into a ball. Divide the dough into four equal pieces. Shape the dough pieces into balls. Wrap the dough balls with cling film and refrigerate for 30 minutes.
3) Working with one dough ball at a time, roll the dough ball into a 30-cm diameter round (the dough should be very thin and almost transparent). Using a fluted pastry cutter, trim the edges to form a square shape. Cut the dough into 2 1/2-cm strips. Cut each strip in half crosswise to form 13-cm-long strips. Gently stretch the strip gently so that you have enough dough to tie a bow. Repeat with remaining dough strips. Gather the dough scraps, then reroll and cut them to make additional bowtie pastries.
4) Line a baking sheet with paper towels. Heat the oil in a large heavy frying pan over medium heat to 190°C. Working in batches, fry the pastries until they puff and become golden, turning once, about 2 minutes in total. Using tongs, transfer the pastries to the paper towel-lined baking sheet to drain the excess oil. While still hot, dust the pastries generously with icing sugar and serve.
The pastries can be made two days ahead. Store in an airtight container at room temperature.