Red Currant Bakery

0 Preheat the oven to 400 F and place a rack in the center of the oven.
Berry Jam Layer
2 In a heavy bottomed pot, pour in the 340 grams of frozen raspberries and 170 grams of frozen blueberries.
3 Add in half of the orange zest, all the lemon zest, sugar, and lemon juice. Simmer over medium heat, stirring frequently to prevent burning, until thick and jammy.
4 Remove from the heat and stir in another 170 grams of frozen raspberries or blueberries (I prefer raspberries).
5 Pour into a large shallow dish and allow it to cool to room temperature while you make the streusel.
Streusel
7 In a medium mixing bowl, add in the soft butter, vanilla, sugar, and salt. Use a fork to combine.
8 Pour in the oats and optionally the chopped hazelnuts. Stir to combine.
9 Finally, pour in the flour and use the fork to rub the flour into the butter mixture.
10 Set aside.
Baked Custard
12 Line a 9" metal round pan with a large sheet of parchment paper that reaches up the sides. An 8" pan will work as well. You can just press the parchment into the pan and crease the paper on the sides so that it lays flat around the edges.
13 In a medium, heat safe bowl, add in the four eggs, egg yolk, sugar, orange zest, vanilla, and salt. Whisk to combine. Place the bowl on a damp rag to keep it from sliding around.
14 Pour the milk in a pot and heat over medium heat, stirring often to keep it from burning. Bring the milk just to a simmer.
15 Once bubbling, slowly pour the milk into the egg mixture while whisking the eggs constantly. DO NOT STOP WHISKING until all the milk is added.
16 Pour the custard mixture into the lined pan.
17 Place in the preheated oven and bake for 10 minutes.
Assemble & Bake
19 After 10 minutes, check the custard, it should be just starting to set on top but still VERY WOBBLY. It just needs to be set enough to spoon the cooled jam on top. If not yet, bake for another 3 minutes and check again.
20 Remove the cake from the oven but leave the oven on.
21 Gently spoon the jam in an even layer on top of the partially set custard.
22 Crumble the streusel on top of the jam layer. Make sure not to clump the streusel too much as it will become difficult to cut through once set.
23 Place the cake back in the oven and bake for another 15-20 minutes. It should still wobble but not slosh. The streusel will be a little pale but still fully baked. Think of it looking a bit like jello when you wiggle it or even slightly jigglier.
24 Take the cake out of the oven once finished baking. Allow it to cool on a wire rack until it comes to room temperature.
25 Once cooled place the cake in the fridge to set for a minimum of three hours or overnight.
26 Dust with powdered sugar before using the tip of a sharp knife to cut through the streusel and then the remaining layers. Don't worry if a bit of liquid has seeped out of the cake, you can pour it off or absorb it with a paper towel.