Preheat your oven to 140°C (285°F) and line a cookie sheet with baking paper.

In a large mixing bowl, beat the butter, icing sugar, flour, and vanilla together for about 10 minutes, until the mixture is very pale, thick, and fluffy. You can use a stand mixer or a hand-held electric beater. Just be sure to whip it long enough for the mixture to become light and creamy.

Using a teaspoon, dollop small portions of dough onto the prepared baking tray, spacing them about 2–3 cm apart. You can leave them as rustic dollops or gently smooth the tops with a damp fingertip if you prefer a more uniform look.

Bake for 13 minutes, or until the edges are set and the tops look dry but still pale—don’t let them brown.

Leave the shortbread to cool on the tray for 5 minutes before transferring to a wire rack. They’ll be delicate when warm but will firm up as they cool.