2 1/4 teaspoons (1 package) instant yeast
2 tablespoons granulated sugar
2 tablespoons butter, softened
4 cups bread flour, plus more for rolling out the dough
1/2 teaspoon salt
About 8 cups neutral oil (like canola or vegetable) for frying, plus more for the bowl
Confectioners’ sugar for topping
1. Heat the buttermilk until it is warm but not hot, about 90°F (it’s okay if it curdles a bit).
2. Using an electric mixer or a stand mixer fitted with the dough hook, mix the yeast, granulated sugar, butter, and buttermilk. Add the flour and salt and mix until the dough pulls away from the sides of the bowl; it will be wet and sticky. If you’re using an electric mixer, the dough will become too thick to beat; when it does, transfer it to a floured surface and gently knead it until it is smooth and elastic.
3. Wipe with 1 teaspoon oil to coat the inside of a large bowl. Transfer the dough to the bowl and cover with plastic wrap or a kitchen towel. Let rise at room temperature for 1 hour.
4. Place a candy thermometer inside a large heavy-bottomed pot or Dutch oven and heat the oil to 375°F while you cut the beignets. Watch very carefully; too-hot oil is a fire hazard and takes a long time to cool down.
5. Roll the dough to 1/2-inch thickness on a well-floured surface and cut it into 2-inch squares. Gently add them to the oil, one at a time; don’t overcrowd the pot. Flip them constantly while they cook. When they are golden brown, transfer them to a paper-towel-lined plate or rack to cool. Top with confectioners’ sugar to taste; to really make these New Orleans style, top each beignet with about 2 tablespoons of it.