Heat the liquidIn a medium saucepan, combine water, butter, sugar, lemon zest and salt.Bring to a simmer over medium heat until the butter is fully melt
Add the flourAdd the flour all at once and stir vigorously with a wooden spoon.Cook for 1–2 minutes, until the dough pulls away from the sides and forms a smooth ball.(This cooks out the raw flour taste.)
Cool the dough slightlyTransfer the dough to a mixing bowl and let it cool for 5 minutes so it doesn’t cook the eggs.
Add the eggsAdd the eggs one at a time, mixing well after each addition.The dough should become smooth, glossy, and pipeable — similar to cream puff dough.
Heat the oilIn a deep pot, heat oil to 350°F (175°C).
Form the zeppoleFor round zeppole: Drop spoonful’s of dough directly into the oil.For ring-shaped zeppole: Pipe dough onto small parchment squares, then lower into the oil and peel off the paper.
Fry until puffed and goldenFry in batches for 3–4 minutes per side, or until deeply golden and fully puffed.Make sure not to overcrowd the pan.
DrainRemove to a paper towel–lined tray to drain excess oil.
FinishDust generously with powdered sugar and serve warm.