Magdalenas

The recipe relies on 60 ml liquid oil, which stays fluid in the batter and keeps the crumb moist and light for days. If you swap in melted butter, use the same amount and let it cool slightly before adding, or it can start cooking the egg mixture. Expect a slightly denser, more buttery crumb and a less pronounced dome than with oil.

The dome comes from the heat shock: the tray must go into a fully preheated 220 °C (430 °F) oven, and only after 5 minutes do you drop to 180 °C (350 °F). Opening the oven during those first minutes or skipping the preheat lets the temperature fall and the tops stay flat. Chilling the filled tray for 15-30 minutes beforehand and filling the liners a good ¾ full also help the batter rise upward rather than outward.

You can refrigerate the batter for a few hours, and the recipe already builds in a 15-30 minute chill, so a longer rest is fine. Keep it covered and stir it only very briefly before filling the liners, since the air beaten into the egg and sugar is what makes them light. Do not leave it overnight if you can avoid it: the baking powder starts reacting once it meets the moist batter and loses lift.

Let them cool completely, then keep them in an airtight container at room temperature; the oil in the batter keeps them soft for a couple of days. Avoid the fridge, which dries them out and dulls the lemon zest aroma. They taste best fresh, so if you want that crunchy sugar top at its peak, bake them the same day you plan to eat them.

Overmixing after the flour goes in - the recipe says to mix just until smooth for a reason, because extra beating develops gluten and gives you tough, tunnelled muffins. The other frequent slip is cutting short the 3-4 minutes of beating the egg, sugar, and salt; that mixture needs to become pale, thick, and airy, since it carries most of the lift. Sift the flour and baking powder as directed so you do not have to stir out lumps later.