This recipe yields one large, 20-cm (8-inch) cake, or two smaller 13-cm (5-inch) cakes.
Ingredients
120g (or ½ cup + 1½ teaspoons) unsalted butter
120ml (or ½ cup) whole milk
3 large eggs
½ teaspoon vanilla extract
300g (or 1½ cups) granulated sugar
170g (or 1⅓ cups) all-purpose flour
2 teaspoons baking powder
¼ teaspoon table salt
Instructions
Start by combining the milk and butter in a small saucepan and heat over low heat until the butter has melted. Pour in a heatproof bowl or mug and set aside to cool to body temperature. In the meantime, preheat the oven to 175°C or 350°F (standard oven setting) and line one 20-cm (8-inch) cake pan or two 13-cm (5-inch) cake pans with baking parchment. I like to line both the bottom and the sides of the pans for this cake, as the parchment allows the cakes to rise evenly and form less of a dome.
NOTE: it is easier to line the pans with parchment if you first very lightly butter the pans. You don't have to be neat about it, the parchment just needs something to stick to.
Once the oven is preheating and the pans are lined, combine the eggs, vanilla and sugar in the bowl of a double boiler and heat, stirring, until the sugar has dissolved and the mixture has warmed to slightly above body temperature. To check whether the sugar has dissolved, rub a little bit of mixture between your thumb and forefinger. You shouldn't feel any sugar crystals. Take the bowl off the heat and mix on high speed for ten minutes, until the mixture is pale and fluffy and the bottom of the bowl feels cool to the touch.
NOTE: by letting the mixture cool, you're basically stabilizing the fluffiness of the eggs and will end up with a fluffier, lighter cake.
In a small bowl, stir together the flour, salt and baking powder. Add the dry ingredients to the egg mixture and, using a rubber spatula, stir until just combined. Give the mixture a quick whizz with the mixer. If you were to start mixing immediately after you've added the dry ingredients, you would end up with a big puff of flour in your kitchen. Check the milk mixture to make sure it has cooled to body temperature and add it to the batter. Mix until smooth and perfect.
Pour the batter into the prepared cake pan(s) and bake for 35-40 minutes for a large cake or 20-30 minutes for a smaller cake, or until a toothpick inserted in the center of the cakes comes out clean.
Let the cake cool for twenty minutes in the pan, then tip onto a wire rack and leave to cool completely. Enjoy on its own immediately or wrap tightly in plastic wrap and chill thoroughly in the fridge before carving. Can be stored, tightly wrapped in plastic wrap, for up to 2 months in the freezer.
Recipe by The Tough Cookie at https://thetoughcookie.com/building-blocks-2/miettes-hot-milk-cake/