Step 1

Preheat the oven to 180 degrees C /375 F.

Step 2

To make the sponge, crack the eggs and add them to a bowl.

Step 3

Add the sugar and beat them until fluffy and the colour becomes a pale yellow.

Step 4

In a separate bowl, mix together the flour, salt, cocoa powder and baking powder and add the dry ingredients to the egg mixture one tablespoon at a time, mixing well with the spatula.

Step 5

Once the dry ingredients are fully incorporated, add the vanilla extract, mix again lightly.

Step 6

Butter and flour a square baking tray of 20x20 cm/9x9 and pour the mixture in.

Step 7

Bake in the preheated oven for about 20 minutes or until risen and firm to touch.

Step 8

Set aside to cool completely.

Step 9

To make the filling, make sure that you remove the butter from the fridge at least one hour before, so that it can be really soft.

Step 10

Place the butter in a large bowl and add the sugar, cocoa powder, nutella and vanilla extract.

Step 11

Use an electric mixer to beat everything well until smooth and creamy.

Step 12

To make the syrup, place the water and sugar into a saucepan and bring it to a boil, stirring until the sugar has dissolved completely.

Step 13

Add the coffee and the vanilla extract, remove from the boil and allow it to cool completely.

Step 14

To make the glaze, break the chocolate into small pieces, add them to a bowl and pour over the milk.

Step 15

Set the bowl over a pan of boiling water and allow the chocolate to melt.

Step 16

Next, cut the sponge into 2 parts and place one part onto the baking tray.

Step 17

Use a brush to brush the cake with the syrup, we want it quite moist, but not too soggy.

Step 18

Next, spread the chocolate filling over the entire cake, place the second part of the sponge on top of the cream and brush it again with the syrup.

Step 19

Top the cake with the chocolate glaze, the refrigerate for at  least 4 hours, ideally overnight.

Step 20

Use a sharp knife to cut the cake into 9 squares, then decorate with whipped cream. Serve chilled.