Step 1

Preheat your oven to 160C / 325F.

Step 2

You’ll be using a lot of hazelnuts in this recipe. It’ll be 4 1/4 cups all up. Place all of the hazelnuts on a baking tray.Bake for 20 minutes or until golden. Allow to cool.

Step 3

Place sugar, water, salt and 1 cup of toasted hazelnuts in a medium sized saucepan on medium high heat. Stir until sugar is dissolved. Add glucose syrup and mix until well combined. Turn heat down to medium and allow to bubble away, stirring occasionally until it turns a deep golden colored syrup. Once it reaches that color turn off the heat and add the bicarb soda. Stir immediately until well combined. Pour onto a baking tray and allow to set for 20 minutes until hard.

Step 4

Break into smaller pieces and place in a food processor. Process until it turns into a paste. Pour into a bowl and cover with plastic wrap. Set aside until ready to use.

Step 5

Add the sugar, cocoa powder, flour, corn starch and salt into a large mixing bowl and use a whisk to combine.

Step 6

Add the egg yolks and about 1 cup of the warmed milk and whisk until well combined. Add the remaining milk and combine.

Step 7

Pour into a large saucepan and use a wooden spoon to stir on medium heat until thickened, about 6-8 minutes. Take off the heat and add about 1/3 of the cubed butter. Stir until well combined. Then add another 1/3 and repeat until it's all in there. Pour into a medium sized mixing bowl and cover with plastic wrap. Chill in the fridge for 4 hours or overnight.

Step 8

Once chilled, add to a food processor and process until super smooth, about 5 minutes. Make sure you scrape down at least once.

Step 9

Add the hazelnut praline and process for 2minutes or until well combined. Place back in the bowl and chill until ready to use.

Step 10

Preheat and oven to 150C / 300C. Spray the bottom (not the sides) of four 8-inch cake tins and line the bottom with baking paper. Set aside.

Step 11

Add the remaining hazelnuts into a food processor and process until they reach a fine crumb texture. Take out two cups of hazelnuts and set aside. You’ll use those two cups for the outside of the cake. Add 1/3 cup of flour into the food processor and process until well combined. Set aside.

Step 12

Add the egg whites and sugar into the bowl of a stand mixer fitted with a whisk attachment. Whisk for 4 minutes or until thick and glossy.

Step 13

Add the vanilla extract and salt and whisk for another 30 seconds. Stop the mixer and add the remaining 1 1/4 cup of toasted and crumbed hazelnuts along with another 1/3 cup of flour. Use a spatula to gently fold through until well combined. Add the mixture to a piping bag.

Step 14

Pipe the mixture into all 4 cake tins.Gently tap on your workbench 3 times. Bake for 15 minutes. Allow to cool completely.

Step 15

Line the bottom of an 8-inch (22cm) springform pan with baking paper.

Step 16

Run a sharp knife around the sides of the cooled cakes to loosen them. Add one layer of cake into the springform pan. Use a piece of acetate measuring 25 1/2 inches (65cm) wide and 3 inches (8cm) high in the cake tin. The cake layer will help keep things in place. Add 1/4 of the chocolate pastry cream and spread around evenly. You can do this using an offset spatula or a tablespoon that has been bent as shown in the video.

Step 17

Add the next layer and repeat until all 4layers have been used. Please note: you will have used 3/4 of the chocolate pastry cream and should have another 1/4 left.

Step 18

To make the vanilla glaze add the powdered sugar to a small bowl along with the melted butter (cooled) and milk, and mix using a whisk until well combined. You may need an extra tablespoon of milk to get the right consistency.

Step 19

To make the chocolate glaze repeat the same process as above using the addition cocoa powder. Thin out using milk if needed.

Step 20

Pour the vanilla glaze on top of the cake and spread around. Add the chocolate glaze to a piping bag and snip the end off. Pipelines on top of the glaze. Use a toothpick or skewer to drag across the chocolate glaze lines. Place back in the fridge for 4 hour or overnight to set.

Step 21

Take the chilled and set cake out of the springform and transfer to a serving plate using the baking paper at the bottom to help you.

Step 22

Slowly unwrap the acetate. Cover the sides of the cake with the remaining chocolate pastry cream. Finish by covering in the remaining 2 cups of toasted and crumbed hazelnuts.