Plum & Cream Pastry Cake

5 from 2 votes

Alternating layers of vanilla cake, puff pastry, pastry cream, and plum butter make up this Plum & Cream Pastry Cake perfect for an August birthday.

Prep Time4

Cook Time2

Resting1

Total Time1 6

Course: Afternoon Kaffee, Dessert

Keyword: birthday cake, pastry cream, Plum butter, puff pastry

Servings:

Calories: 520kcal

Equipment

9" x 13" metal pan

Ingredients

Plum Butter

8 black plums
2 tablespoons light brown sugar
150 grams water

Pastry Cream

100 grams corn starch
240 grams sugar
1/2 teaspoon fine sea salt
800 grams milk
200 grams heavy cream
8 egg yolks
80 grams salted butter
2 teaspoons vanilla bean paste

Vanilla Cake

2 eggs standard large, room temperature
140 grams granulated sugar
1/4 teaspoon fine sea salt
1 teaspoon vanilla extract
100 grams full fat greek yogurt
90 grams olive oil
40 grams heavy cream
150 grams all purpose flour
1/2 teaspoon baking soda
1/2 teaspoon baking powder

Puff Pastry

2 sheets puff pastry thawed but cold
80 grams granulated sugar

Chocolate Ganache

90 grams 60% chocolate
100 grams heavy cream
30 grams salted butter

Instructions

Plum Butter

Rinse, pit, and dice the plums into 1" chunks.In a large heavy bottomed pot, add in the plums, light brown sugar and water. Cover with a lid and place over medium low heat.
Cook for about 10 minutes until the juices are bubbling up past the chunks of plum.
Remove the lid and continue cooking and stirring until all of the plums and their skins have broken down.
Keep cooking and stirring until thick and the mixture no longer looks thin and watery. This usually takes about 15-20 minutes.
Once thick, remove from the heat and set aside to cool.
Transfer to a large shallow dish to let it cool completely while you move onto the next step. It doesn't need to be fridge cold but it can be!

Pastry Cream

In a large pot, whisk together the corn starch and sugar. *If you need to do this in two batches you can! Then pour in the milk and heavy cream and whisk to combine. Add in the egg yolks, salt and whisk once more.
Place the pot over medium low heat and whisk constantly scraping the bottom and edges of the pot. It will feel like it’s taking a while but all of a sudden it’ll get really thick so don’t stop whisking. *It will get really thick, don’t stress.
Once thick, remove the pot from the heat and whisk in the butter and vanilla bean paste until smooth.
Pour the cream through a fine mesh sieve into a large shallow bowl or on a quarter sized baking sheet. Cover the surface with a layer of plastic wrap to prevent a skin from forming.
Once cooled to room temperature, transfer the cream to the fridge and let it chill completely - this one needs to be fridge cold!

Vanilla Cake

Preheat the oven to 350 F and place a rack in the center of the oven.
In a medium bowl, whisk together the eggs, sugar, salt, and vanilla extract until smooth.
Add in the heavy cream, yogurt, and oil and whisk again.
Lastly, pour in the flour, baking soda and baking powder.
Whisk once more until combined and smooth.
Scrape the sides and bottom of the bowl.
Spray a 9" x13" metal cake pan with your baking spray and then pour in the vanilla batter.
Smooth out the cake with a rubber spatula.
Bake in the hot oven for 10 minutes, then rotate 180 degrees and bake for another 8-10 minutes until the edges are golden brown and a toothpick comes out clean.
Leave the cake to cool for 10 minutes in the pan, then flip the cake out onto a sheet of parchment and leave it to cool completely.

Puff Pastry

Turn the oven up to 400 F and defrost the puff pastry according to package instructions. Keep an eye on the pastry, it still needs to be cold!
Line a baking sheet with a piece of parchment paper. Lightly dust the work surface with a bit of flour. Lay one sheet of defrosted pastry on the floured surface.
Sprinkle the surface with 40 grams of granulated sugar. Use a rolling pin to roll the pastry out into a thin layer that is at least 9"x13" and the sugar has pressed into the surface.
Transfer the pastry to the parchment lined baking sheet. If any spot tears, carefully press it back together.
Use a fork to prick the surface all over, I'm talking ALL OVER.
Bake for 15 minutes in the hot oven, then rotate 180 degrees and bake for another 5-10 minutes until pale golden brown.
Set aside to cool and repeat rolling out the pastry and baking with the second sheet.

Assemble

Once all elements have been made and cooled off, it's time to assemble.
Cut the cooled vanilla cake in half to create two rectangles that are 9" x 6.5". Then cut each of those into two layers.
Take one piece of cake as a guide and use a serrated knife to cut the pastry into 4 rectangles of the same size. Save the scraps!
Remove the plastic from the surface of the pastry cream. Use a whisk or a hand mixer to beat until smooth.
Rinse out the 9"x13" pan we used to bake the cake. Line half of the pan with parchment paper - ideally you want the sheets to stick up a couple inches past the top of the pan. They will flop over for now but we'll stick them to the sides of the cake once it's stacked.
Lay one layer of pastry into the lined side of the pan pressing it into the edge of the pan. Scoop about 3/4 of a cup of pastry cream onto the pastry and use an offset spatula or the back of a spoon to spread the cream carefully over the pastry all the way to the edges.
Scoop about 70 grams of plum butter onto the pastry cream and spread it out, stopping just short of the edges so leaving a border of cream uncovered.
Lay one layer of cake over the plum butter and press down gently. Repeat with the cream and plum butter, using the edges of the pan to keep the cake straight and stable.
Repeat all steps starting with the next sheet of pastry, then cream, plum butter, cake, cream, plum butter - until all the layers have been used up.
Once the last layer of cake is on, scoop any remaining cream over top of the cake and spread it out to evenly cover the top and use any excess to fill in gaps on the side of the cake.
Press the excess parchment onto the sides of the cake and cover the top with a sheet of plastic. Transfer the pan and cake to the fridge to set for at least 24 hours - even 48 is great.

Chocolate Ganache

Once the cake has set, it's time to make the ganache. *If you don't want to coat it in ganache you could make an extra 1/4 batch of pastry cream to cover the cake with once set and then stick the crushed pastry scraps to it!
For the ganache, melt together the chocolate and heavy cream in a microwave safe bowl or pot on the stove. Once the cream is hot, let it sit for a couple minutes then stir with a whisk until smooth.
Add in the butter and whisk again until it has melted in. Let the ganache cool for about 10 minutes, stirring occasionally to keep a skin from forming.
Unwrap the cake and place it on a wire rack. Trim any sides if things aren't quite even.
Pour the ganache over top of the cake and use an offset spatula to gently spread the ganache over top.
Crush the pastry scraps and crumble them over top of the cake.
Place the cake back in the fridge to set for at least 20-30 minutes. This will keep the chocolate from dragging down into the cake layers.
When ready to serve, use a long serrated bread knife to cut slices that are at least an inch thick. I recommend cutting thick slices as they will hold together better and then cut the slices in half or into thirds.

Notes

Tips for making a Plum & Cream Pastry Cake

*If you are short on time, aka you can't let the cake sit for 24-48 hours, or you just don't want puff pastry. Make two batches of the vanilla cake and swap out the pastry for more cake. This will only need to sit for 4-6 hours in the fridge and will also be delicious!
The worst thing you can do with this cake is to assemble it while the elements are still warm. If you want to split making this cake over 3 days you absolutely can. Just prepare all of the elements except the puff pastry on day 1. On day 2, bake the puff pastry, let it cool, and assemble the cake. Let the cake set overnight and then enjoy on day 3.
You can absolutely make your own puff pastry but I prefer to just buy it frozen. Make sure to keep an eye on it when defrosting - I find that a lot of packages say to let it defrost for a long time at room temperature which would make it too warm.
Make sure the puff pastry has been rolled thin and is nice and cold before baking.
Cook the pastry cream low and slow and don't forget about it. It will take a while to begin to thicken and then all of a sudden it will go from liquid to quite thick and stiff.
If your puff pastry get's any big bubbles just smoosh them down - ideally when baking but worst case you can do it when you're assembling!
I love topping this cake with a chocolate ganache but you can always top it with more pastry cream and the flaked puff pastry.
If you would rather a larger shorter cake, don't cut the cake in half first, just cut it into two layers (although you can cut it in half to make it easier to cut the layers and then just place them side by side when assembling). Then trim the two layers of puff pastry to be the same size as the cake and stack so that you have two layers of cake and two layers of pastry instead of 4 and 4.

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