How to Make It
In a medium bowl, mix the warm water with the sugar and yeast. Let sit for 10 minutes until foamy.
In a large bowl and using a hand mixer, beat the eggs with the vanilla and evaporated milk until smooth. Beat in 4 cups of the flour and the salt until smooth. Beat in the yeast mixture until smooth. Beat in the butter until incorporated, stir in the remaining 3 cups of flour. Cover and refrigerate the dough for at least 2 hours or up to 24 hours.
In a large enameled cast-iron casserole, heat 4-inches of oil to 360°. Line a large rimmed baking sheet with paper towels. Remove the dough from the refrigerator and roll out to a 1/4-inch thick rectangle. Cut the dough into 2 1/2-inch squares. Fry the dough in batches until they begin to float and are golden brown, about 1 minute. Using a slotted spoon, transfer the beignets to the prepared baking sheets and repeat with the remaining dough. Dust with powdered sugar and serve.