Preheat your oven to 180°C (350°F) and prepare a 9-inch springform tin by greasing and lining it with baking paper.

In a large bowl, combine the plain flour, cold unsalted butter, and caster sugar. Rub the butter into the flour until it resembles coarse breadcrumbs.

Stir in a pinch of salt, one beaten egg, and a splash of vanilla extract. Mix until a dough forms and chill for 15-20 minutes.

Roll out the pastry, line with parchment and fill with baking beans. Bake for 15 minutes, then remove beans and bake for another 5-10 minutes.

Prepare the rhubarb by chopping it into small pieces and tossing with granulated sugar and lemon juice. Let it macerate for 10 minutes.

Whisk together eggs, caster sugar, and cornflour until smooth, then gradually add double cream or milk, whisking continuously.

Spread the rhubarb onto the cooled crust, pour the custard mixture over it, and smooth it out.

Bake the torte for 30-35 minutes until the edges are set but the center is slightly wobbly.

Cool in the tin for 30 minutes, then refrigerate for at least 2 hours before slicing.

Dust with icing sugar before serving.