Filling bundt cakes: beyond 'tunnel of fudge'

[Wholemeal Crank]

I remember making bundt cakes with 'baked-in' filling, and now I wonder:  would a basic fruit curd stand up to being baked in the middle of a bundt cake without horrible texture fail?

 

Could something like this basic curd work, chilled enough to allow it to be applied with a pastry bag over the half-filled bundt cake batter, and topped with more batter?  Dreaming now of a pistachio cake with pomegranate filling, but thinking about other combinaions as well--what are the key characteristics required in a 'bake-in' filling?

 

2/3 cup sugar
2 T cornstarch
1 cup pomegranate juice
1/4 cup lemon juice

5 egg yolks, whisked together

1/3 cup butter, cut into chunks

Stirred the sugar, cornstarch and juices together until there were no lumps, then brought it to about 160 degrees. Gradually added it to the whisked eggs, returned to heat, brought to near boil so the cornstarch thickened, then strained it into a bowl, whisked in the butter, and poured into serving dishes to chill.

[blue_dolphin]

This isn't going to answer your specific question (especially you can't access it behind the NYT paywall) but they recently published a recipe for Olive Oil Bundt Cake with Beet Swirl which certainly goes beyond 'tunnel of fudge' 🙃  

[Wholemeal Crank]

I'm a subscriber so can get behind the paywall, sort of.....they want me to pay even more for access to their back recipes.

 

But I can see the recipe above, and it's about altering a bit of the batter, which is another way to approach the issue:  I could take the base cake batter and mix a portion of it with pomegranate molasses and swirl that in, which would get a lot of the same flavor elements, but not the curd texture I'm dreaming about. 

[teonzo]

Personally I would avoid egg yolks and butter, they would mask the pomegranate taste. I would avoid lemon juice too.

 

I made something similar years ago, here is the photo:

 

 

They were "saccottini" made with sweet potato dough (Italian sweet potato, which is grey) and a pomegranate filling. It's different from a bundt cake in the sense that in my case the dough was a laminated yeasted dough, so during the cooking process it's "harder" than a bundt cake batter, but I don't think there are risks for the filling to run out of the cake batter.

 

I used this recipe:

 

50 g   cornstarch

450 g    pomegranate juice

120 g    sugar  (I used cane sugar to make it vegan)

 

Put cornstarch in a pot, add about 50 g pomegranate juice, whisk to dissolve the cornstarch and break all the lumps (if you add all the pomegranate juice then it's harder to break all the lumps). Add the remaining pomegranate juice and the sugar, whisk to dissolve. Cook whisking constantly, when it starts making the first bubbles then lower the flame to the minimum, keep cooking for other 2 minutes (always whisking). Let it cool, then use.

 

Result had a soft "creamy" texture, should be what you are looking for.

 

 

 

Teo

 

[heidih]

Tunnel cakes were a thing in the 70's. Not necessariy baked in - but tunneled out after baking. My mom's entertainment dessert  for special folk  was angel food split  and tunneled  out. (innards pulled out) with a stunning black cherry mousse "tunnel".  

[Wholemeal Crank]

5 hours ago, teonzo said:

Personally I would avoid egg yolks and butter, they would mask the pomegranate taste. I would avoid lemon juice too.

 

I made something similar years ago, here is the photo:

 

 

Those look delicious!

 

I am specifically asking about this curd, which I created as part of a different dish (a tart with apples and pomegranate curd), and I loved the pomegranate curd as written , with the richness of the eggs and the butter.  What I am wondering about are the limits of a cornstarch/egg curd or custard being used to 'fill' a cake by being baked inside it--will they separate or liquify or come out (when cooled) as a thick sliceable center to a slice of cake?

 

Today I went simple and prepared a pomegranate curd to pour over the pistachio cake.  There's lots of room for improvement because I discovered that pomegranate molasses has too strong of a 'cooked' flavor already to substitute for pomegranate juice, although the intensification of the pomegranate flavor was pleasing against the relatively bland cake. 

 

I think the way to go for practice is small-batch cupcakes with dollops of filling to see how each filling is affected by being 'baked in'.  Walk before I run....

 

[Wholemeal Crank]

4 hours ago, heidih said:

Tunnel cakes were a thing in the 70's. Not necessariy baked in - but tunneled out after baking. My mom's entertainment dessert  for special folk  was angel food split  and tunneled  out. (innards pulled out) with a stunning black cherry mousse "tunnel".  

 That sounds delicious.   But I'd rather be lazy and 'bake it in' than to hollow out and keep it neat. 

[JeanneCake]

When I use lemon curd as a tart filling, I sometimes put the tart in the oven for 5-10 minutes to set; it's the same principle as lemon bars. I'm going to venture a guess that you'd want to layer the cake batter in,  chill it, use a spoon to make a moat, put the cold curd in the moat then pour the rest of the batter over it.

[teonzo]

11 hours ago, Wholemeal Crank said:

I am specifically asking about this curd, which I created as part of a different dish (a tart with apples and pomegranate curd), and I loved the pomegranate curd as written , with the richness of the eggs and the butter.  What I am wondering about are the limits of a cornstarch/egg curd or custard being used to 'fill' a cake by being baked inside it--will they separate or liquify or come out (when cooled) as a thick sliceable center to a slice of cake? 

 

Ah, I thought that recipe was new to you, so things are different.

 

Possible problems with your recipe are these ones:

1- curd's egg proteins coagulate during the cake cooking process, so the curd becomes grainy;

2- cake cooking process breaks the curd's emulsion (lots of butter there), so the curd becomes grainy;

3- curd becomes too runny during the cake cooking process, so it ends up being (partially) absorbed by the underlying cake batter.

 

Case 1 should not apply here: you already cooked the egg yolks while making the curd, so there should be no risk.

Case 2 could happen, most custards that are baked in the oven don't have troubles but some do, it depends on the single recipe and the cooking process. I would say this is possible but chances are small.

Case 3 is more probable. You have the cornstarch that binds water, but there is that lot of butter that liquefies before the cake batter starts setting (egg proteins are still uncooked, starches are not gelatinized). This is the more worrysome risk, especially if it's combined with case 2.

Only way to know is trying.

 

 

 

Teo

 

[Wholemeal Crank]

10 hours ago, teonzo said:

 

Ah, I thought that recipe was new to you, so things are different.

 

Possible problems with your recipe are these ones:

1- curd's egg proteins coagulate during the cake cooking process, so the curd becomes grainy;

2- cake cooking process breaks the curd's emulsion (lots of butter there), so the curd becomes grainy;

3- curd becomes too runny during the cake cooking process, so it ends up being (partially) absorbed by the underlying cake batter.

 

Case 1 should not apply here: you already cooked the egg yolks while making the curd, so there should be no risk.

Case 2 could happen, most custards that are baked in the oven don't have troubles but some do, it depends on the single recipe and the cooking process. I would say this is possible but chances are small.

Case 3 is more probable. You have the cornstarch that binds water, but there is that lot of butter that liquefies before the cake batter starts setting (egg proteins are still uncooked, starches are not gelatinized). This is the more worrysome risk, especially if it's combined with case 2.

Only way to know is trying.

 

 

 

Teo

 

 

Thank you, this is exactly what I was groping towards asking.  I think I have figured out a way to test this with much smaller batches as cupcakes, and will report back on how it goes. 

[teonzo]

There is a way to minimize risks:

- prepare the pomegranate curd, then the pistachio cake batter;

- prepare one single cupcake, made with pistachio cake batter and inside a dollop of the pomegranate curd;

- cook the single cupcake and see what happens, if it's ok then you go on with your initial plan (pistachio cake with the pomegranate curd filling), if it's not ok then you prepare a standard pistachio cake, then fill it with the pomegranate curd after it's cooked and cooled.

This way you waste a single cupcake at most.

 

 

 

Teo

 

[teonzo]

I was forgetting an important thing: shelf life.

If you succeed in making the filled bundt cake, then beware for how much time you store it and where you store it. That pomegranate curd does not have long shelf life at room temperature, I doubt it can reach the 2 days mark. So be careful about this, since we are talking about a whole cake and it's possible you are planning to eat it in multiple days. If so, store it in the fridge. It's a problem for the cake part, since it becomes tough due to the butter hardening. You can warm the slices in a microwave, but there is another problem related to this: the curd will heat much more than the cake part, due to the much higher water content.

 

 

 

Teo

 

[Wholemeal Crank]

The plan was to prepare this for a potluck party, with no concern for leftovers past about 36 hours. 

 

But it's another good point.

[teonzo]

Please report back, thanks!

 

 

 

Teo

 

[blue_dolphin]

I'll be interested in hearing how it works.  As you probably did, I googled fruit curd bundt cakes and found a number of recipes. Some had visible curd but in others, it seemed to have melted or been absorbed by the cake, sometimes even by people using the same recipes. Most of them were lemon curd/lemon cake so there wasn't much contrast either way.  Your particular combination of pinkish curd and greenish cake has the potential to become anrather unpleasant brownish shade if it doesn't stay separate.  I'm sure the flavors would be delightful either way.

[Margaret Pilgrim]

On 5/30/2019 at 2:02 PM, heidih said:

Tunnel cakes were a thing in the 70's. Not necessariy baked in - but tunneled out after baking.

 

Indeed tunneled out after baking.     From mid-century Betty Crocker Picture Cookook

[rotuts]

@Margaret Pilgrim

 

I have that same book from the low '50's

 

it was my mothers

 

and I loved leafing through all those pages 

 

and so many pictures !

 

the binder and the punch holes made it something special for me

 

its still a treasure for me

[Margaret Pilgrim]

There is a lot of wisdom in that book.    My m-i-l introduced me to Poteca, an Austrian/Yugoslav walnut-filled bread.    She told me that it was close to impossible to make, only passed down grandmother to mother to daughter.    And, lo and behold, there it is on page 117 of the BCPC.    Simple and correct.    No discernible differences between mine via BCPC and my grand-m-i-l's.   

[rotuts]

Exactly So .