Chocolate Chiffon Cake

Preheat oven to 320°F/ 165°C / Gas Mark 3

Grease and line 2x 8-inch round pans (or 3 x 7-inch round cake pans) - set aside

Dry ingredients - Combine the flour, baking powder, and salt. Sift the flour mixture will give a light and airy chiffon.

Cocoa paste - Pour boiling water into the cocoa powder and create a paste. Set aside to cool. Pro tip - make sure to use a whisk to prevent lumps in the cocoa paste.

Separate the eggs - Carefully separate the egg yolks and the egg whites making sure no egg yolks get into the egg whites otherwise the whites won't whip to stiff meringues.

Place the yolks in the bowl of a stand mixer with the whisk attachment. Whip with half the sugar until light and fluffy. Pro tip - when whipped the mixture will be very pale and light in color.

Gradually, add the oil followed by the vanilla extract, cocoa paste, and flour. Set aside

Clean the bowl of the stand mixer and whisk attachment, then add the egg whites and whip with the remaining half of the sugar until stiff peaks form. Pro tip - any grease in the bowl or whisk will not whip the egg whites so clean it properly. Also, add the sugar gradually into the egg whites to get the most volume.

Gently fold the whipped egg whites into the cake batter with a spatula making sure not to overmix.

Pour batter into the prepared baking pans - tap a few times to remove any air pockets. Pro tip - You can also use a 12 cup bundt or 10-inch tube pan

Bake on the center rack for 25 to 30 minutes or until a skewer inserted in the center comes out clean.Pro tip - if you use a single bundt or tube pan the cooking time will be longer about 60 to 65 minutes

When done invert immediately onto a cooling rack and cool completely before decorating.Pro tip - run a knife around the cake to release it from the pan before inverting so it does not get stuck.

Watch my video on how to make Swiss meringue buttercream

Melt the chocolate in a microwave-safe bowl or double boiler. Set aside to cool.

Place egg whites and sugar in the bowl of the stand mixer with the whisk attachment.Pro tip - make sure the bowl is grease-free otherwise the egg whites will not whip

Using a whisk, place the bowl over a double boiler and constantly whip until all the sugar has dissolved and the egg whites are fairly warm (about 160 F).Pro tip - you don't need a thermometer, as long as all the sugar has completely melted your eggs are ready to use

Take the bowl off the heat and whip the egg whites until you have a thick meringue with stiff peaks.Pro tip - it is best to start whipping eggs at medium speed then increase speed as you go for the best meringue

Let the mixer continue to whip on medium-low until the mixer bowl feels cool to touch. Then gradually add butter, one cube at a time, with the mixer at medium speed.Pro tip - it is VERY important that the meringue is cooled completely before you add the butter otherwise you will have a soupy mess.

Once all the butter is added, whip on medium-high for 2 minutes. Add the vanilla. Combine well until everything is well combined.

Finally, add the melted chocolate and Kahlua. Combine well until you have a smooth chocolate buttercream.Pro tip - it is very important that the chocolate is not warm when added to the frosting otherwise it will seize.

Once cooled, cut the domes off the cake layers using a serrated knife. Brush each layer with Kahlua or simple syrup.Pro tip - simple syrup is just sugar and water boiled for 3 minutes. It keeps the cake layers moist.

Place a cake layer on the cake board or cake stand.Pro tip -if you plan to move the cake, it is best to use a cake circle under the cake, so you can pick the cake with its base and without any accidents.

Top with a big dollop of buttercream - spread evenly using a straight-edge spatula. Place the next layer followed by more buttercream.

Frost the two layers with a thin layer of buttercream. Chill for 10 minutes.Pro tip - Chilling the cake at this point will ensure the layers don't move when you frost the outside. Though, if you leave the cake uncovered in the fridge for too long it can dry out. So, 10 minutes is all you need.

Place the remaining buttercream in a piping bag with the star piping tip. Pipe straight lines from the bottom to the top all around the cake. And pipe swirls on the top.