I made this filling for Ava’s birthday cake and let’s just say, she was lucky I didn’t sneak into the kitchen in the middle of the night to lick it all out of the centre, it was that delicious.
The filling is a variation on Warren Brown’s Italian Meringue Buttercream (IMBC) which I have mixed with a sticky date pudding sauce to make a caramel meringue filling for Ava’s caramel mud cake……yum yum YUM!
Before we get stuck in to making our IMBC, we need to make our caramel sauce so that it has enough time to cool down and thicken.
Bring to the boil:
150g Brown sugar
And then simmer 5 minutes before setting aside to cool down and thicken up
Next it is best to measure out our ingredients for the IMBC.
5 egg whites from extra-large eggs
455g of unsalted butter, cut into small pieces and set aside so that it can come to room temperature
285g castor sugar, plus 55g in another bowl
1/4 cup water
When making Italian Meringue Buttercream (IMBC) you need to make sure your bowl is completely clean from the last use. Egg whites wont whip properly if there is remaining fat in the bowl, so I like to clean my bowl and whisk attachment with some alcohol.
So… grab your trusty bottle of vodka from your handbag 🙂 and a paper towel and give everything a good clean.
Next up, separate your eggs and start your mixer on a slower speed… gradually working up to the highest speed as the egg whites start to bubble.
At this point, you can put your 285g sugar and water into a pan over a high temperature with your sugar thermometer (you can use the thermometer to stir the sugar until it has dissolved).
I know you are thinking ‘what the heck is a sugar thermometer?’ and yep, I was thinking the same thing when I first read the recipe. You can pick one up off ebay for about $10 and it is really important to have one to gauge when your sugar syrup is at the right temperature (if you leave it that bit too long, it will turn into caramel).
While your syrup is boiling away, your egg whites should be nice and fluffy, so keep the mixer on and add in the remaining 55g sugar
Keep the mixer on and go back to your stove to check on your syrup. It needs to boil until the temperature reaches 249F.
Your mixer should still be running (in fact, from the moment you turn your mixer in, it should remain on until you have finished the whole recipe), so carefully pour the boiling sugar syrup into the mixing bowl
Ideally it would have been great to have shown you a pic of me pouring the sugar syrup into the mixing bowl, but the combination of a heavy SLR camera, boiling hot sugar syrup and 3 children watching me was not ideal!
If you put your hands around the mixing bowl, you’ll notice that it is quite hot. The mixer needs to keep beating until the mixing bowl is at room temperature (or thereabouts). It generally takes about 10mins and in this time the sugar syrup is cooking the meringue (yum yum).
Once the bowl is at room temperature, grab your butter and one by one, drop it in the bowl (if your mixing bowl is smaller than mine, you may want to place a tea towel over the top of it so that bits of butter and meringue don’t fly around the room.
Keep mixing for a few minutes until it is all combined
I made this batch of IMBC to fill two cakes, so it does make a decent amount, but any leftover can be stored in the fridge in an airtight container for a few weeks.
I mixed about 1/3 of the IMBC into my caramel sauce
I used this filling for my 6″ mudcake which I levelled using my cake leveller because I don’t trust myself to cut straight myself! This is really easy to use as you adjust the notches on the size for the preferred height and then you saw away and end up with an even cut.
I generally bake my mud cakes in advance and then freeze as I find they are much more moist this way (and it helps save time). I also prefer to level and tort my cakes before they have fully defrosted.
Once you have made your layers, it is simple to just cover each layer and set aside ready to ganache and ice.