In a mixing bowl, combine the flour, baking powder, sugar, and salt.
In another container, combine the oil and the warm milk. Now, make a well in the center of the flour and pour the milk mixture in.
Stir everything until combined.
Use your hands to form a ball of dough.
Knead the dough gently for a few seconds into a smooth ball then cut the dough into 4 pieces. Place the dough pieces back in the bowl and cover it with a towel. Let the dough rest for 20 minutes.
In a heavy pan, pour 2 inches of oil and use a candy thermometer clipped to the side of the pan to heat the oil to 350°F.
On a floured surface, roll out the dough until it's about 1/4 inch thick.
Cut the dough into 2-3 inch squares depending on how large you want the pastries and how many you would like.
When the oil reaches 350°F carefully lower 5-6 pieces of dough into the pan. Do not overcrowd them in the pan. Spoon some hot oil over the top of the dough to help it puff up. When the dough has puffed up and the bottom side of the pastries are slightly browned, flip them over and cook the other side. Keep in mind the dough cooks quickly.
Drain on a paper towel. To keep the cooked sopapillas warm while finishing the rest of the batches, pop them in an oven at 200F to stay warm.
Serve these tasty treats with powdered sugar and honey.