Chrusciki with Mrs. Kostyra

Put melted butter, eggs, egg yolks, granulated sugar, sour cream, salt, extracts, vinegar, and rum in the bowl of a standing mixer fitted with the paddle attachment. Beat on medium-high speed until mixture is pale, about 3 minutes. With mixer running, add zests. Reduce speed to low, and gradually add up to 3 cups flour, 1/2 cup at a time, until a fairly stiff dough forms.

Turn out dough onto a lightly floured surface, and knead, dusting with flour if it seems sticky, until dough becomes smooth, soft, and elastic, about 10 minutes. Halve dough, and wrap each piece in plastic wrap. Let dough rest at room temperature, 30 minutes.

Working with 1 piece at a time, roll out dough on a lightly floured surface until very thin (about 1/16 inch thick). Using a straightedge as a guide, cut the dough into 5-by-1 1/4-inch strips. Trim ends on the diagonal.

Lay dough strips vertically in front of you, and cut a 1 1/4-inch-long opening through the middle of each strip. Working with one strip at a time, push one end through the cut, then pull through to make a bow-tie shape. Transfer formed chrusciki to a large parchment-lined baking sheet, and cover with a clean, slightly damp kitchen towel. Repeat process with remaining dough.

Heat shortening in a large (6-quart) pot over medium-high heat until it registers 375 degrees on a deep-fry thermometer.

Working in small batches of about 7, fry chrusciki, turning once with a slotted spoon, until lightly browned, about 1 minute. Transfer fried chrusciki with slotted spoon to two paper-towel-lined baking sheets to drain. (Adjust heat between batches as necessary to keep oil at a steady temperature.)

Just before serving, dust chrusciki with confectioners' sugar.