All the ingredients should be at room temperature.
- Divide the eggs into whites and yolks.
- Whip the whites until half-whipped, and add half of the sugar amount. Keep whipping, increasing the speed to maximum. You need the stable peaks.
- Whip the egg yolks with the remaining sugar until whitening. Add the oil and sour cream, and mix it all.
- Sift the flour, baking powder and salt.
- Now, add 1/2 of the yolk mass and 1/2 of the dry mix to the meringue. Combine it all, using a spatula. Be very careful, not to spoil the fluffiness. Do all the same with the remaining halves of the yolk mass and the dry mix.
- Pour the batter into two 6.30 inch (16cm) molds, and bake at 347-356F (175-180C) for about 30 minutes.
- Cut each sponge biscuit in two before assembly.
- Combine the milk and sugar, and bring it to a boil.
- Cool the soaking, and soak each cake layer before assembly.
- Brew the currants in a saucepan for about 5 minutes. Mash it with a blender, and cook to 113-122F (45-50C).
- Mix the sugar with the starch, and pour this mixture into the berries in a thin stream.
- Bring the mass to a boil, and cook for a couple of minutes until it thickens (don't forget to whisk!).
- Put the mass in a different container, cover with film in contact, and let it cool.
- Combine the COLD ingredients in a bowl, and whip for a minute at a medium speed.
- Gradually increase the mixer speed, and keep whipping for 4-5 minutes until fluffy. The frosting will be dense and very pleasant to use.
- Put 200g (7.05 oz) of frosting aside, and add about 10g (0.35 oz) of confit to it, to get the desired color. You'll use this frosting for leveling the cake.
- Put the first biscuit layer on the board, and soak it.
- Next, pipe the frosting sides, using a pastry bag. Now you have the outer circle.
- Then, pipe the confit circle inside, very tight to the previous (frosting) one.
- Repeat it all once again: a frosting circle - a confit circle. And finish with the frosting in the middle.
- Assemble the whole cake, following that order.