Kumquat marmalade sour cream loaf cake – air fryer tested!

A rich and moist loaf cake, studded with juicy kumquat pieces from the marmalade and topped with a sour cream frosting.

A super simple recipe – cream butter and sugar, add eggs, alternate wet and dry.

Plus, I tested this recipe both in the air fryer and in the oven, so no excuses!

Jump to recipe

Ok so I’ve seen the air fryer memes, and I get it. I think they’ve been too hyped up and overrated in a sense because to me it’s basically like a mini oven and most of the people raving about air fryers are people who are generally quite well off, already have an oven, and can already afford to use their oven for little things like keeping their French toast warm. Everything they are so amazed about can already be done in an oven, whether it be with the regular settings or the grill setting. I remember the thing that was always advertised was being able to cook chips (fries) in it without extra oil. But that can already be done in an oven???

In saying that, they’re basically just mini ovens, meaning they heat up REAL FAST thus using less power (ok so maybe those people just want to be more energy efficient… but idk, I never really hear it as an argument). So imo it’s actually pretty perfect for those a) without an oven b) who live alone or with one other person, or c) who want to use their oven less/ cannot afford to use their oven more often or for small things.

Anyway, this is not an air fryer advertisement, just some thoughts I had.

In this case, my oven was actually broken so I thought I’d try making a recipe for the air fryer (because of the aforementioned similarity to ovens). Air fryers come in many different forms. I noticed that mine doesn’t heat the bottom very well (the heating element is located at the top), so when cooking something thick like a cake, you need to cook it low and slow, covering the top with baking paper when it gets too brown, otherwise the top will be fully cooked, and you’ll think it’s fully cooked (the fully cooked top will scrape any raw batter off the skewer when you pull it out) until you take it out of the pan and have a look.

The reason I include both a foil option and a baking paper option for covering the cake if it’s browning too much is that one works well for an oven, and the other for my small air fryer. I found that in my air fryer covering it with foil doesn’t allow enough room for the heat to properly circulate and instead prevents the cake from cooking properly. I found that covering the cake in baking paper allowed the heat to still reach the cake yet reduce the direct heat and thus reduce browning to the top.

Anyway, so about kumquats. Do you eat kumquats whole? I remember, just once, reading that you’re meant to eat them, skin and all, so that it doesn’t taste as sour. Ever since then, I’ve eaten them whole, and it really does make them taste less sour. But are you ‘meant’ to eat them like that? Are you meant to embrace the sourness? Am I just weak?

Recipe

For the cake

INGREDIENTS:

  • 125g castor sugar
  • 4g lemon zest (approx. 1.5-2 lemons)
  • 125g unsalted butter, softened
  • 2 eggs
  • 80g sour cream
  • 70g kumquat marmalade (or other marmalade of choice)
  • 60g lemon juice
  • 1/4tsp baking soda
  • 1/4tsp salt
  • 150g self-raising flour

METHOD:

1. Line a 21x11cm loaf pan and preheat your oven to 170°C or prepare your air fryer (mine does not require preheating, for example) for baking at 150°C (for an air fryer that needs to cook things low and slow) or 170°C.

2. Rub together, with your fingers or a spoon, the sugar and lemon zest. Beat it together with the softened butter until very pale in colour and fluffy.

3. Beat the eggs in one at a time, ensuring they are fully incorporated before adding the next. Set aside.

4. Prepare the rest of the liquid ingredients by first stirring the sour cream to loosen it up. To it, add the marmalade and lemon juice and mix to fully combine. Set aside.

5. Prepare the dry ingredients by sifting together the baking soda, salt, and flour. Set aside.

6. Bring back the butter and egg mixture. To it, add 1/3 of dry ingredients and mix on a low speed until just incorporated (a few flour streaks is fine). Beat in 1/2 of the liquid ingredients until just incorporated. In the same way, beat in another 1/3 of the dry ingredients (1/2 of the remaining mix), then remaining milk mixture, then lastly the remaining flour mixture.
Fold the mixture to ensure everything is fully combined. Do not overmix.

7. Pour the batter into the prepared loaf pan and spread it out evenly. For an oven or an air fryer that doesn’t need to bake low and slow, bake at 170°C for 35 minutes or until a skewer comes out clean and the cake bounces back when lightly pressed. Cover with foil or baking paper if the top is browning too quickly. Avoid opening the oven within the first 25 minutes.
For an air fryer that needs to bake low and slow, bake at 150°C for 90 minutes, covering the top with baking paper if it starts to brown too much. Make sure to avoid opening the air fryer within the first 30 minutes.

8. Remove from the oven/ air fryer and poke holes through the top with a skewer. Generously brush on the syrup (see recipe below) whilst the cake is still warm. Leave in the pan to cool fully.

9. Once cooled, spread the icing (see recipe below) on top and decorate with sliced kumquats if desired.

For the syrup

INGREDIENTS:

  • 50g lemon juice
  • 50g castor sugar

METHOD:

1. Place both ingredients into a small pot and heat until boiling, stirring constantly. Lower the heat slightly and simmer for 3 minutes.

For the icing

INGREDIENTS:

  • 120g unsalted butter, softened at room temperature
  • 80g sour cream, at room temperature
  • 80g icing sugar

METHOD:

1. Stir the sour cream to loosen it up. Set aside.

2. With an electric mixer, beat the butter until light and fluffy.
Beat in the sour cream until fully combined, then sift and beat in the sugar, a little at a time, until smooth and fluffy.

That’s it – enjoy!

Leave a comment