Españoletas aragonesas (Spanish cake cookies)

Crack three large eggs into a large bowl and finely grate in the zest of half a lemon, avoiding the white pith, which is bitter.

Whisk until light and frothy, about one to two minutes.

Slowly add 250 g granulated sugar while whisking so it incorporates evenly.

Whisk in 90 ml extra virgin olive oil until well mixed.

Add 14 g baking powder and a quarter teaspoon of sea salt; keep whisking while slowly adding 240 g all-purpose flour, switching to a spoon as it thickens, to a thick, creamy batter. Thin with a little milk if too thick, or add flour if too thin.

Pipe from a Ziploc bag with the end cut off (or drop spoonfuls) onto a parchment-lined baking tray, each a little bigger than a walnut and well spaced, as they spread.

Bake in a preheated oven on top and bottom heat at 180C (355F) for about 10 to 12 minutes, until light golden brown; 5 minutes less for a softer cookie.

Rest at room temperature a couple of minutes; serve as is or dusted with powdered sugar.