Red Currant Bakery

Pflaumenmus (Plum Butter)
33 The night before you plan to make these bars (or up to 5 days in advance), you need to macerate the plums so they can be cooked into a plum butter the next day.
34 To macerate the plums, rinse and dry them. Then remove any stems and cut in half lengthwise around the pit to remove it. Place all of the pitted plums into a large pot or bowl. I used a coated cast iron dutch oven which works perfectly but don't use one that isn't coated as the sugar and acid will be too much for the exposed iron.
35 Pour in the granulated sugar and stir to combine. Optionally add in two teaspoons of cinnamon at this time.
36 Cover the pot or bowl and leave it to sit at room temperature overnight.
37 Place a small plate in your freezer, this will be used to test the plum butter.
38 When you are ready to cook the plum butter the next day, remove the cover and place the pot with the macerated plums (if they were in a bowl, transfer them to a pot at this step) over the lowest heat possible.
39 You want to cook this plum butter low and slow, stirring frequently to prevent the sugar from burning. This takes about an hour but could be a little less or more depending on how many plums you're cooking.
40 Continue cooking until the mixture has thickened to the point where you don't really see any plum juices running around.
41 To test the doneness of the pflaumenmus, take the plate out of the freezer and spoon 1 tablespoon of it onto the plate. Allow it to sit for 30 seconds to a minute. Then, when you wipe the jam off with your finger it should wrinkle and be quite thick.
42 Once cooked, remove from the heat and pour the plum butter into an airtight container and store in the fridge until ready to use.
Pudding
44 In a small sauce pot, whisk together the cornstarch, sugar, and salt.
45 Pour in the milk, heavy cream, and egg yolk and whisk again.
46 Place the pot over medium heat and whisk. Continue to whisk until the mixture thickens and just starts to bubble and thicken.
47 Remove the pot from the heat and stir in the butter and vanilla extract until the butter has fully melted.
48 Pour into a large shallow dish to cool. Lay a piece of plastic wrap on the surface to prevent it from forming a skin.
Dough
1 In the bowl of a stand mixer add in the flour, sugar, and yeast, then whisk to combine. 
2 Add in the warm milk, butter, egg, salt, and vanilla.
3 Use the dough hook attachment to knead the dough on medium speed until just combined and then turn it down to low and knead until smooth and the sides of the mixing bowl are clean.
4 Shape the dough into a ball and place in a lightly greased bowl, cover with a lid or plastic and place somewhere warm to rise for 45 minutes or until doubled in size. 
5 Preheat the oven to 350 F and arrange two racks so that they divide the oven into thirds. 
Assemble
10 Line one baking sheet with parchment paper or a silicone baking mat.
12 Once doubled in size, lightly sprinkle the dough with flour and punch out the air from the dough. I recommend not re-kneading it because this will tighten the gluten making it difficult to roll out but just be sure to smoosh out all of the air.
13 Lightly flour your work surface and pat the dough into a skinny rectangle. Gently roll the dough out to approximately 30 cm x 50 cm. I recommend rolling the short end closest to you a little thinner so the center isn't too thick.
14 Spread 30 grams of the very soft butter over the entire surface of the dough. I recommend doing this with a pastry brush or an offset spatula.
15 Spoon the plum butter over the thin butter layer and use an offset spatula or a rubber spatula to spread it over the whole surface of the dough, all the way to the edges.
16 Starting with the short side closest to you, roll the dough up tight but not too tight that all of the jam squeezes out.
17 Use a knife and ruler to mark the log into 6 even slices.
18 Use the same sharp knife to cut the roll into slices. Lay each of the slices onto the lined baking sheet. Tuck about a 1/2" of the end of the swirl under each roll.
19 Gently press down on top of each slice, it will be a little messy, but this helps to give them their characteristic large swirl.
20 Tuck about a 1/2" of the end of the swirl under each roll.
21 Gently press down on top of each slice, it will be a little messy, but this helps to give them their characteristic large swirl. 
22 Press the center of the swirl down to make a little well. Spoon about 2-3 tablespoons of the vanilla custard into the center well.
23 Leave the rolls to proof for about 20 minutes, they should look like they have grown slightly and are a little puffy.
49 Once proofed, bake the rolls for 15 minutes in the preheated oven. Then rotate the pan 180 degrees and bake for another 15 minutes until golden brown.
Finishing
31 Once baked and slightly golden brown, take the baking sheet out of the oven and place on a wire cooling rack.
32 Immediately brush the browned dough with 30 more grams of butter. Then leave them to cool for at least 5 minutes before serving dusting with powdered sugar.
50 Last but not least, fill a piping bag with the remaining pudding and pipe it into the center where the baked pudding is. Careful not to push the tip of the bag too far down so that it doesn't squeeze out of the bottom.