In the bowl of a stand mixer, using the paddle attachment, combine 2 ½ cups flour, buttermilk powder, sugar, yeast, and salt. Add water and eggs to flour mixture. Blend at low speed until moistened. Beat 3 minutes at medium speed.

Switch to the dough hook and mix in the remaining flour a little at a time, to make a soft dough, add more or less flour as needed. Knead the dough for 5 minutes until smooth and elastic.

Place dough in lightly oiled bowl and turn to grease top. Cover; let rise in warm place until double about 30 minutes.

Add oil to a deep fryer or large pot until it is 2 inches deep. Heat oil to 360°.

Punch down dough. On a floured surface, roll the dough into a 18 x 12-inch rectangle. Use a pizza cutter to cut the dough in six rows, each 3 x 12-inches. Cut each row in to four 3-inch squares.

Carefully drop 3 beignets in oil and fry until puffed and golden brown, about 3 minutes, flipping frequently. Repeat with remaining dough.

While beignets are still hot, sprinkle heavily with powdered sugar. Serve immediately.