Get the oven going and line your tin. Heat the oven to 175°C (155°C fan, Gas Mark 3½). Line a 20 cm round cake tin or a 900 g loaf tin with parchment paper, letting the paper come up the sides a little — this makes lifting the cake out effortless later. You want the oven fully up to temperature before the batter goes in, so start this first.

Whisk the dry ingredients. In your mixing bowl, combine 250 g plain flour, 2 tsp baking powder, ½ tsp bicarbonate of soda and ¼ tsp salt. Give it a quick whisk for about 20 seconds — you will see the powders turn pale and evenly blended, with no streaks of soda left behind.

Add everything else and beat briefly. Tip in 200 g caster sugar, 2 eggs, 240 g yogurt, 120 ml olive oil, 2 tbsp lemon zest, 60 ml lemon juice and 1 tsp vanilla. Beat on low for 30–40 seconds, just until the flour disappears. The batter should look glossy, pale gold and slightly thick — like a loose custard. Stop the moment it comes together; overbeating makes a tough cake.

Scrape and pour. Run a spatula around the bowl to catch any flour hiding at the bottom, give one last fold, then pour the batter into the lined tin. Smooth the top with the back of a spoon — it should sit level and fill the tin about two-thirds of the way up.

Bake until deeply golden. Bake for 42–48 minutes. At the 40-minute mark, open the oven and take a look: the top should be a rich golden brown, the edges just pulling away from the paper, and the centre should feel springy when you press it lightly with a fingertip. A skewer inserted into the middle should come out with a few moist crumbs, not wet batter.

Cool in the tin for 15 minutes. Set the tin on your wire rack and leave it alone. You will hear a faint crackling as the crust settles — that is normal. After 15 minutes, lift the cake out by the parchment and let it finish cooling on the rack. Slicing too early gives a gummy edge, so patience here pays off.

Finish and serve. Dust with icing sugar through a small sieve just before serving, if you like. The crumb should be soft, slightly damp and fragrant with lemon the moment you cut into it.