In a food processor, pulse together the flours, salt, baking powder, and sugar. Add the lard or shortening and pulse to combine. Add the buttermilk and pulse until a moist dough forms. Transfer to a lightly floured work surface, and knead several times until it binds into a cohesive mass. Cover with plastic wrap and let rest for at least 30 minutes.
Pour oil to a depth of 4 inches into a heavy saucepan and heat to 375 degrees F. Meanwhile, divide the dough in half. On a lightly floured work surface, roll out half of the dough 1/8 to 1/4-inch thick. Cut into 6 squares or triangles. Drop 2 cutouts, 1 at a time, into the hot oil and fry, rolling them over, until golden, 40 to 50 seconds. Drain on paper towels. Repeat with the remaining dough.
Serve at once on warmed plates with scoops of ice cream, cream anglais or dusted with powdered sugar or cinnamon sugar.
This recipe was provided by a chef, restaurant or culinary professional. It has not been tested for home use.