Preheat your oven to 350°F (175°C).
Prepare your baking sheets by lightly greasing them or lining them with parchment paper.
In a mixing bowl, combine the sugar, beaten egg, and sour cream until well mixed.
Gradually add in the flour, baking soda, and salt, ensuring everything is thoroughly blended.
Divide the dough into two equal portions.
Shape each portion into a long roll.
If your kitchen is warm, keep the dough you're not working within the fridge to prevent it from becoming too soft.
Take a small slice of dough and, on a lightly floured surface, roll it with your hands into a pencil-thin strip about 7 inches in length.
Shape the strip into a figure "8," pressing the ends together to secure the shape.
Place the cookies onto the prepared baking sheet.
Repeat with the remaining dough.
Bake in the preheated oven for 12 to 15 minutes, or until the cookies are lightly golden.