Ingredients

• 3 cups Organic Unbleached White All-Purpose Flour
• 2/3 cups Cocoa Powder
• 1 tsp Salt
• 1 tsp Baking Soda
• 1 1/2 cups Granulated Sugar
• 2 tsp Instant Coffee Powder
• 1 cup Melted Butter
• 2 cups Milk slightly warm
• 1 Tbsp Vanilla Extract
• 1/4 cup White Distilled Vinegar

• 1 Tbsp Water
• 1 1/2 Tbsp Vanilla Custard Powder
• 1/4 cup Sugar
• 1 cup Milk
• 1 Tbsp Butter

• 3/4 cup Butter (softened at room temperature)
• 2 1/4 cups Powdered Sugar
• 1 1/2 tsp Vanilla Extract
• 3/4 Tbsp Heavy Cream
• 4-5 drops Blue Liquid Food Color

• 1/2 tsp Baking Cocoa powder
• 3/4 Tbsp Water warm

Instructions

1. First, add all the dry ingredients listed under "For Cake" (flour, cocoa powder, salt, baking soda, sugar, coffee powder) to a large mixing bowl. Mix well until combined.
2. In a separate bowl, add the melted butter, milk and vanilla extract. Mix well until combined.
3. To the dry ingredients, add the wet mixture. Mix well until everything is combined into a smooth cake batter.
4. Preheat the oven to 375°F. Now, to the cake batter, add the vinegar. As soon as you add the vinegar the batter, it will react with the baking soda and turn white. Fold the cake batter until the vinegar is combined with the batter. It is perfectly fine when you see white streaks.
5. Grease a 13 x 9-inch pan and line with a parchment paper. Transfer the batter to the baking pan. Bake for about 25 minutes until the cake is done in the center. A toothpick inserted in the middle should come out clean. Pull the cake from the oven and transfer to a cooling rack to cool completely.
6. While the cake is cooling, we will prepare the custard filling. Mix the custard powder and sugar to the water. Add the butter to the mixture.
7. Add the milk to a pan and heat in medium flame. While the milk is hot, add the custard powder mixture along with butter and mix well ensuring that no lumps are formed. Keeping stirring until the custard thickens. Turn off the flame and let it cool for 5 minutes. Transfer to the refrigerator and let it cool down until needed.
8. Now moving on with the icing. In a mixing bowl, add the softened butter, confectionery sugar, heavy cream and vanilla extract. Using a hand mixer, beat in low speed until combined and fluffy. Add the food color and beat in medium speed until combined and fluffy. Keep aside.
9. Now, we will move back to the cake. Once the cake is cooled, cut it into two halves. Then, slice a small portion from the top of the cake to make sure that the cake surface is flat. Now, cut the cake pieces in the shape of a egg. Use an egg shaped paper cut out to guide you.
10. Add a little bit of the icing on top of the cake stand. Transfer one of the cake pieces to the cake stand. Place small sheets of parchment paper under the cake so that it doesn’t get messy while icing.
11. Then, using a spoon, gently scoop out some of the cake from the middle of both the pieces to form a hole in the middle. The hole should be shallow and not too deep.
12. Now, to the shallow hole in the middle, add the custard filling. Take the other piece of cake and gently place it on top of the first layer, with the hole side down.
13. Add a little icing to the top of the cake and spread it out evenly with a spatula. Do the same to the sides of the cake. Refrigerate the cake for 5 minutes. Pull the cake out and add one more layer of icing. This will ensure that the cake bits don't mix with the icing and seen through.
14. Finally, to complete the speckled effect, mix the cocoa powder and warm water in a small bowl. Use a stiff pastry brush, dip it into the cocoa mixture and spray onto the cake. Make other decorations as you wish, like adding edible pearls, chocolate bites, etc.