Method
STEP 1
Heat the oven to 180C/160C fan/gas 4. Butter and line the bases of two 20cm sandwich tins. Melt the butter in a pan, then remove from the heat and beat in the oil, milk, yogurt, vanilla and eggs. Whisk the dry ingredients together with a large pinch of salt, squishing any lumps of sugar with your fingers. Tip the wet ingredients into the dry, then whisk until smooth.

STEP 2
Divide the batter between the tins and bake for 25-30 mins on the same shelf of the oven until risen and a skewer inserted into the middle comes out clean. Leave to cool for 10 mins in the tins, then transfer to a rack to cool completely.