• NOTE: The cooking time above is  based on using all three baking pans in the oven at once. Otherwise, if you choose to use only one pan and bake in three separate batches, the  cooking time will be 45 minutes.

Chocolate ganache

• Place heavy cream (whipping cream) in a small saucepan over heat or in a heatproof jug to microwave. Heat until hot but DO NOT let it boil – it might cause the chocolate to split or go grainy. Turn off the heat and take the pot off the stove.
• Add chopped dark chocolate or chocolate chips to the saucepan. Leave the chocolate in the hot cream to soften for about 3 minutes.
• Stir the ganache until it becomes smooth, then allow it to cool on the counter without covering it (at room temperature).
• Set it aside to cool while you get the cake batter ready and bake the cake. During this time, the ganache will cool and thicken, making it suitable for spreading.

Preheat the oven and prepare the baking pan.

• Preheat the oven now to 325°F / 170°C (150°C)if you are using a fan assisted oven)
• Grease and line three 8×8-inch (20x20cm) baking pans with parchment paper.
• If you only have one 8×8-inch (20x20cm) baking pan, bake each portion of batter one after the other.) I used the same pan and baked the cakes in 3 batches.
• To get the best results, make sure you're using a pan that's 8 inches (20 cm) or smaller. If you go bigger, the cakes will turn out too thin.

Prepare the batter

• In a large bowl, beat the eggs, caster or white granulated sugar and vanilla extract.
• Add melted butter and whisk until incorporated.
• Sift in all purpose flour, baking powder and salt. Whisk well to get a smooth batter.

Divide the batter

• Divide the batter into 3 equal portions. (I weighed to be sure of equal amounts)
• Add unsweetened cocoa powder and 2 - 3 Tablespoons of milk to one of the portions. Whisk well to combine.

Bake

• Transfer the batter evenly between the three prepared baking pans, or, if you're using a single pan, bake the cakes in three separate batches.
• Bake at 325°F / 170°C (or 150°C for fan-assisted ovens) for 15 minutes.
• While in the oven, each cake layer will typically rise to around 1 inch (approximately 2.5 cm) in height.
• Let the cakes remain in the pans for 5 minutes, then transfer each cake to a cooling rack to cool completely.

Assemble

• Spread half of the chocolate ganache evenly on top of the first vanilla cake.
• Position the chocolate cake on top of the ganache-covered vanilla cake.
• Spread the remaining ganache over the chocolate cake.
• Finally, place the second vanilla cake on top of the chocolate cake.
• Trim the edges of the cake to form a neat square.

The glaze topping

• Mix powdered (icing) sugar and slowly add 2-4 tablespoons of warm milk or water until you've got a smooth, thick frosting.
• You want it spreadable, not drippy, just right for the cake's top without running down the sides.
• Use a spatula to spread the glaze over the entire top surface of the cake.
• Top with chocolate sprinkles if you like.
• Leave the glaze to set for about 30 minutes before slicing.

Serving

• You can choose to keep the cake as a square or create two rectangular cakes by splitting the cake in half to form two rectangle-shaped cakes.
• Slicing the square cake into two rectangles makes it easier to control portion sizes. This is especially helpful when you're baking for an event, celebration, party, or in professional settings like bakeries or restaurants where uniform portions are important

Storage

• At room temperature: in an airtight container for up to 3 days,
• In the refrigerator: in an airtight container for up to for up to 5 days.
• Please refer to the post for guidance on how to store the plain cakes in the freezer.