Chocolate Castella Cake

Medium
12 pieces
10 minutes
75 minutes
"130g (1/2 cup) unsalted butter
130ml (1/2 cup + 2 tablespoons) milk
80g (2/3 cup) all-purpose flour
40g (3/8 cup) unsweetened cocoa powder
A pinch of salt
8 eggs, separated
1 teaspoon vanilla extract
Zest of orange
130g (1/2 cup + 2 tablespoons) granulated sugar"
"1- Preheat the oven to 284 °F (140°C). Place parchment paper on the bottom and sides of a square cake pan (20cm).
2- Separate the whites from the yolks.
3- In a pot over medium heat, put the butter and milk and leave until the butter melts.
4- In a bowl, sift the flour, cocoa powder and salt. Then add the milk and butter mixture and combine well.
5- Add the egg yolks and mix well. Then add the vanilla extract and orange zest and mix until the mixture is smooth and well blended.
6- In a separate bowl, place the egg whites and whisk until foamy.
7- Add the sugar and continue whipping until the egg whites have stiff peaks.
8- Add the meringue to the yolk mixture in three batches and mix gently with a spatula until the mixture is well combined.
9- Pour the castella batter into the cake pan, place it in a larger baking tray, and add boiling water until halfway through the cake pan.
10- Cook the castella for 75 minutes or until firm to the touch.
11- Remove the castella pan from the water and leave the castella to cool completely, then serve it at room temperature! "