Name: Plum cake tatin
Prep time: 15 min
Cook time: 60 min
Yield: 6
Cuisine: French
Ingredients: 85g unsalted butter, at room temperature, plus extra for greasing dish; 10 to 12 purple plums, cut in half and pitted; 390g caster sugar; 2 extra-large eggs, at room temperature; 75ml sour cream; 1/2 tsp grated lemon zest; 1/2 tsp pure vanilla essence; 170g plain flour; 1/2 tsp baking powder; 1/4 tsp salt; Icing sugar, for dusting