In the bowl of an electric mixer, combine the sourdough starter, flour, granulated sugar, buttermilk, melted butter, and salt.
Knead on low speed for 5 minutes, until all the ingredients are combined and the dough forms a ball that is slightly sticky.
Place the dough in a lightly greased bowl, cover with plastic wrap and allow to sit on the counter in a warm spot for 4 to 6 hours. It should be almost doubled in size.
Place the bowl in the fridge, and allow to ferment overnight, or up to 48 hours.
Heat a large skillet with about 2" of canola oil in it until hot (about 325 degrees)
Lightly flour the counter.
Roll the dough out into a large rectangle about ¼" thick.
Cut the dough into squares about 3”.
Working with 4-6 squares at a time (don't crowd your skillet!) drop the dough into the hot oil, flipping them often until they are golden brown and puffed. This will literally take a few seconds, so don't walk away!
Transfer to a cooling rack set over a baking sheet for a few seconds and then dust with powdered sugar.
Repeat with remaining dough.
Enjoy while they are still warm!!!
