Today’s recipe started as a vehicle for frosting to use up some of the leftover burnt caramel sauce from this. I'm not sure how, but it quickly degenerated into a quest to replace my old faithful chocolate cake recipe. I’ve never been that happy with the way it bakes in my steam oven, so it was high time to fix things. Along the way I ended up tossing the caramel frosting because it was just TOO much (I know! Who would have imagined that could be possible?!), so now, here we are, finally, at what I’d like to call a simple steam oven chocolate cake with a simple frosting. It’s a not unhappy place to be, but the way is littered with chocolate cake cast-offs deemed unworthy of further development. My husband’s work colleagues must either be thrilled with their bounty of ok-but-not-perfect cakes, or never want to see a chocolate cake again.
In the many years I’ve been cooking and developing recipes using a combi steam oven, I’ve learned a few things about steam oven cakes and baking. The first is that you can adapt almost any ‘regular’ cake recipe to be cooked in your steam or combi steam oven, but you probably shouldn’t. I mean, mostly they’ll come out ok, but as you may have heard before, baking is a science, involving chemical reactions between various ingredients plus (usually) leavening/raising agents and heat. So if you’re trying to cook a recipe in your steam oven which you’ve made for years in a standard convection oven (exactly where I was at before this crazy cake show kicked off), it will likely bake up with an entirely different texture than you’re used to. The biggest reason for this: steam is in itself a leavening agent, and will impact the way your cakes and other baked goods rise in the oven. Sometimes that will be to their benefit, but if you don’t understand exactly what’s going on with your ingredients you might be in for a not so happy surprise in the form of a peaked, over-risen cake with enormous cracked canyons running across the top, or something which is so dense and pudding-like it almost isn’t a cake at all. Want a brief lesson in leavening agents, baking and steam ovens? Read on! Or if you’re only here for the cake, just continue on down the page to the recipe (I won’t be offended, promise).
So here it is – most cake recipes employ one or a combination of baking powder, baking soda, air, steam and yeast to make them rise during baking. We’ll leave yeast-risen cakes out of this particular discussion, but there’s a more in depth summation of how that works here if you’re interested.
Baking powder and baking soda as leavening agents
Baking soda and baking powder look pretty similar, and their purpose in baked goods is similar: to provide leavening via the release of carbon dioxide. That does NOT mean they’re directly interchangeable, though, because they work in different ways.
Baking soda, also sold as sodium bicarbonate or bicarbonate soda, is a base which needs an acid to react with it in order to provide the tiny bubbles of carbon dioxide which make your baked goods rise. Some examples of acids you might add to baked goods include lemon juice, vinegar, buttermilk, sour cream, honey, and cocoa (there are lots of others!). Baking powder is a ready-mixed acid and base combination which, when it gets wet, will react to form carbon dioxide. So you can use it in baked goods where you don’t want to add anything else acidic to the mix.
So if a recipe asks for baking soda but you don’t have any, you can use baking powder instead (though you’ll have to use roughly double the stated quantity). You can’t replace baking powder with baking soda, though, unless you add something acidic as well. Cream of tartar will work if need be – I substitute ¼ tsp baking soda and ½ tsp cream of tartar for every 1 tsp baking powder. It’s not a perfect swap and probably won’t rise as much as the baking powder would have, but it will do in a pinch. I don’t suggest using more of the baking soda + cream of tartar mix to get more rising as too much baking soda can leave your baked goods with a bitter, fizzy aftertaste.
Air as a leavening agent
This one is pretty simple. If you can get air into your batter or dough, it provides lift to your baked goods. Generally this is in the form of beating butter or egg whites a lot to incorporate air bubbles, then carefully mixing in the remaining ingredients in order not to knock out too much air before baking. Using air as a leavening agent is very often (but not always) done in conjunction with baking powder or baking soda.
Steam as a leavening agent
This is where things get interesting, fantastic and sometimes frustrating when you’re baking in a steam oven. Steam acts as a leavening agent in all baked goods to some degree, because the water content in your food will turn into steam when it gets hot enough, causing the molecules to spread out and the food to expand. The extra moisture in the oven cavity when you use a steam oven means the water in your food doesn’t evaporate as quickly – that’s great for retaining moisture and tenderness but can create chaos with baked goods in particular.
Can we bake a cake now?!
Almost! I'm trying to bring things neatly back to steam oven chocolate cake. The go-to recipe I’ve made for about the past fifteen years is quite heavy (in a good way), with an almost-mud-cake texture when made in a conventional oven, but in the steam oven it was giving me all sorts of trouble. The recipe uses baking powder as a leavening agent, and for some reason I still can’t explain, the combination of the baking powder and steam was causing the cake to rise so quickly and so much that it kept ending up with huge cracks and peaks on top. Worse, in large round cake or loaf cake form it baked up with a huge hole through the middle, which is pretty unattractive when cut! The giant holes didn’t happen when I made it in cupcake form but I was still getting those cracks. It really bothered me despite the fact the texture and taste were really great. After much experimentation I have settled on a couple of things. I don’t know if these apply to every cake baked in a steam oven (though I’ve found them to also be true for carrot cake and pound cake), but they certainly work as far as this one is concerned.
The first thing I’ve done is adapt my recipe to one using baking soda. The lift it gives to the cake in the steam oven is lovely but not so extreme that it causes the aforementioned cracking and holes.
But the biggest change? Layers, people. Before I began using a steam oven for a lot of my cooking, I baked most cake recipes as one single large cake (and I have baked A LOT of cakes in my lifetime). If I wanted them to become layer cakes I just split them after baking, and that has always worked well for me – the texture of my cakes was even and they didn’t require multiple tins to be greased and lined. Now? I am more than happy to grease and line an extra tin, because using my steam oven I can get the cooking time to less than half of any previous efforts, and the texture is SO GOOD. Lighter than a mud cake but heavier than a sponge, with a soft, moist crumb and keeping qualities which extend for days. Incidentally, if you want to see the difference between baking as one single cake or as two separate layers, have a look here. The one with the peaks and valleys is today’s recipe baked in a single tin for 55 minutes, and the other two are exactly the same recipe split in half and baked in the same tin for 22 minutes apiece. What you can’t see in that photo is the difference in the crumb – the split batch is even, soft and springy while the one-tin batch is heavy and dense under a thick and uneven crust (it’s not a bad cake even then, but side by side the split batch is the outright winner for both looks and eating).
So the final result, after all the experiments, is the recipe below – Simple Steam Oven Chocolate Cake. It uses two bowls and a whisk. No melting, no beating, and, if you’re lazy like me, not even any sifting. I’d call that a pretty great recipe and you can bet it’ll be my new go-to cake for baking in the steam oven at our house. I hope you like it.
Recipe: Simple Steam Oven Chocolate Cake
This makes one 22cm/9” cake with two layers. If you’d like to make it in a smaller tin I’d suggest splitting the batter in thirds and adjusting the cooking time down a few minutes, because the deeper the batter, the higher the risk of the dreaded cracked top and too-dense texture.
You’ll see there is no chocolate in the cake, only cocoa. Use the very best you can afford – my absolute favourite is this one. Yes, that's a pretty big bag, and yes, I buy it in that quantity. It keeps for ages in a cool, dark place and I find I get through a bag or two a year. Their chocolate is also fantastic and worth buying in bulk so long as you can stop yourself eating it all before you bake with it). You’ll taste the quality of the cocoa in the finished cake and I always figure there’s no point wasting your time in the kitchen for inferior baked goods.
I’ve called for milk + lemon juice below because it’s what I most often have available, but if you have buttermilk hanging around in your fridge, use that instead as your acidic component.
I have given a really simple recipe for a sour cream chocolate frosting below – it’s essentially a ganache using sour cream instead of cream. The sourness cuts the richness of the chocolate just a little, but you still get a deeply flavoured and really silky frosting. Don’t be tempted to use ‘light’ sour cream, the water content means your frosting might seize.
The frosted cake will keep, covered, for about 4 days.
250g (2 cups) plain flour
220g (1 cup) caster sugar (white or raw, doesn’t really matter)
100g (½ cup, firmly packed) dark brown sugar
70g (¾ cup) Dutch process cocoa
2 tsp baking soda (sodium bicarbonate)
½ tsp salt
250ml (1 cup) whole milk
1 tsp lemon juice
2 large eggs
250ml (1 cup) vegetable, almond, grapeseed or other light flavoured oil (coconut oil is pretty popular and it’ll probably work but I really don’t like it in baked goods as I feel like I can taste it over everything else)
1 tsp vanilla extract
250ml (1 cup) water
1. Grease and line the bases of two 22cm/9” cake tins (or one if that’s all you have – you can turn out the first cake, pour the batter in for the second and bake in two batches. The second cake won’t rise quite as much because the batter sits around, but the difference is negligible). I have these great cake tin liners which I love and try to always keep around.
2. Preheat your oven to 160⁰C (combination steam mode). If your oven has variable steam settings, use 60%.
3. Put all the dry ingredients in a large bowl and give them a whisk to combine (I don’t sift but if your baking soda in particular is lumpy, give it a quick sieve so you don’t end up with fizzy lumps in your cake).
4. Put all the wet ingredients except the water in another bowl or a large jug and whisk to combine. Pour this wet mixture into the dry mixture and whisk until it’s just smooth. Add the water and mix gently to incorporate.
5. Divide the batter between your two tins and bake them for about 22 minutes, or until they’re springy and test clean with a skewer. Leave to cool in tins for 5-10 minutes before turning out to cook completely.
Sour Cream Chocolate Frosting: Melt 400g dark chocolate, then stir in 300g room temperature full fat sour cream until it’s incorporated and you have a smooth, shiny mixture. You can use it straightaway as a pouring consistency frosting (if you only want a thin coating), or wait for it to cool and thicken slightly before spreading over the cooled cakes.
But I don’t have a steam/combi-steam oven! Preheat your oven to 170⁰C and bake the layers for around 25 minutes apiece, until they test clean with a skewer.
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