Attach the dough hook to your electric mixer and set it to the lowest speed. Combine the flour, baking powder, salt, egg, softened butter, and milk in the mixing bowl. Gradually add the water in small increments while keeping the speed on low. The precise amount of water may vary, so add just enough for the dough to become soft yet manageable, ensuring it doesn’t adhere to the bowl’s sides.

Let the mixer knead the dough for 15 minutes. The dough should feel slightly tacky but remain cohesive. Cover and allow it to rest for 30 minutes. If kneading by hand, extend the kneading time by an additional 5 to 10 minutes.

Lightly flour a clean surface and shape the dough into a uniform, flat rectangle, approximately 4 inches wide and ¼ inch thick. Carefully place the dough onto a large sheet of plastic wrap, ensuring it is completely covered. Secure the ends of the wrap underneath the dough, then set it on a baking sheet or flat plate. Refrigerate overnight.

The next morning, remove the dough from the refrigerator and let it rest at room temperature, still wrapped, for at least 1 to 3 hours. The dough must return to a very soft consistency before frying. This process may take longer in colder environments, so be patient—this step is crucial for achieving the right texture.

Prepare a wok or deep pan for frying, ensuring it is large enough to accommodate long crullers. Pour in enough oil to create sufficient depth, then gradually heat it over medium heat until it reaches 400-425°F (205-220°C).

Meanwhile, unwrap the dough and gently invert it onto a lightly floured surface. Carefully peel away the plastic wrap and dust the top with a small amount of flour. Slice the dough into 1-inch-wide strips, aiming for an even number. Stack two strips together and press firmly down the center with a chopstick to bind them. Holding both ends, stretch the dough until it reaches about 9 inches in length.

Once the oil has reached the correct temperature, carefully lower a stretched piece of dough into the hot oil. If the temperature is ideal, the dough should immediately rise to the surface. Using long cooking tools such as chopsticks or tongs, continuously roll the dough in the oil for about a minute to ensure even frying.

Fry one or two pieces at a time, ensuring each cruller is consistently rotated. When they achieve a light golden brown hue, remove them from the oil. Avoid overcooking, as they should remain chewy rather than overly crisp.

Repeat with the remaining dough. For efficiency, consider having one person prepare and stretch the dough while another manages the frying process.