Grease and line a 9-inch spring-form cake pan with parchment
Beat together the butter and sugar until pale and fluffy.
Beat in the eggs bit by bit.
Combine the dry ingredients and sift into the egg mixture.
Fold in until incorporated.
Pour the batter into the prepared cake tin and spread out evenly.
Spread 1 cup of the pastry cream evenly on top of the batter.
Remove the rhubarb, reserving the syrup, and scatter over the cake.
Bake for about 1 hour in the oven (lowering the heat if the top gets too dark). A skewer inserted into the middle of the cake should come out clean, although the pastry cream will remain a bit wet.
Remove from the oven and allow to cool slightly before drizzling with reserved rhubarb syrup.
Directions to make the pastry cream:
In a saucepan, heat the milk with the vanilla pod and seeds.
In a separate bowl, whisk together the eggs and sugar, and add the corn starch.
When the milk has just reached the boiling point, remove from heat and pour 1/3 of it into the egg mixture while whisking continuously.
Pour the egg mixture back into the remaining hot milk, whisking continuously.
Return to heat and bring to a boil, carefully.
Whisk continuously as the mixture thickens, for just under a minute
Remove from heat and stir in the salt and butter.
Pour into a cold bowl and cover with cling wrap to prevent a skin forming.
The mixture will keep in the fridge for a few days.
Directions to make the rhubarb topping:
In a pan set over a low heat, melt the butter, then stir in the sugar and cardamom.
Add the rhubarb, stir to coat in the butter and stew for 2–3 minutes.
Set aside to infuse.
Notes
Adapted from: ScandiKitchen: Fika and Hygge by Bronte Aurell