Heat the milk in a small saucepan over medium heat until small bubbles form on the surface.
Remove from heat, add the buttermilk, then pour into a stand mixer bowl.
Add the yeast and sugar, mix and let rest for 5 minutes.
Add the flour, baking soda, and salt, and mix at low speed, using a dough hook, until the dry ingredients are moistened, 3 to 4 minutes. Increase the mixer speed to medium and continue mixing until the dough forms a sticky ball, 1 to 2 minutes more.
Cover the bowl with plastic wrap and let the dough rise, 1 hour.

In a large saucepan, pour 3″ (7.5 cm) of oil and heat to a temperature of 375 F (190 C), over medium heat.
Line a plate with paper towels and set aside.

Lightly flour your work surface.
Sprinkle the top of the dough with flour, gently press down, fold in half, and gently fold the ends to the middle to form a ball.
Flour the dough again and roll it out to a thickness of 1/3″ (0.8cm).
Let the dough rest for 1 minute before using a pizza cutter to cut the dough into 1 and 1/2″ (4 cm) squares.

Gently drop the dough pieces into the hot oil, a few at a time, and fry for 2 to 3 minutes, turning frequently with a slotted spoon.
Transfer to the prepared plate and let cool.
Generously sprinkle with powdered sugar and enjoy.