Fill a large saucepan with water and bring it to a simmer. 

In a large heatproof bowl, combine sugar and eggs. Place the bowl over the pot of simmering water and whisk the mixture until sugar completely dissolves.

Add pieces of butter and honey to the bowl and whisk until the butter is melted.

Add baking soda to the bowl and whisk. The mixture will begin to foam and increase in size. Keep whisking until it thickens a bit and increase approximately 2 times.

Remove the bowl from the pot of simmering water and let the mixture cool down for 3 minutes. 

When the batter cooled down, sift 360 g of flour (working in batches) on top and mix it in using rubber spatula. 

Transfer the batter to a working surface generously dusted with flour. If the dough feels too sticky, add up to 100 g flour. The dough should remain warm and playable.

Form a disk and wrap the dough in a plastic wrap. Place it in the fridge for 1 hour.

Preheat the oven to 180 C/ 350 F. Tear off 7 pieces of parchment paper (large enough to fit 23 cm/ 9 inches layer on it)

Transfer the dough from the fridge and divide it into 7 parts. 

Lightly dust the surface of one parchment paper with flour. Place one ball of the dough on top and sprinkle it with flour. 

Using a rolling pin, roll the dough working from the center towards the ends. It should be even in thickness and a bit larger than 18 cm/ 7 inches.

Transfer the dough with parchment paper to a baking sheet and place it in the oven. Bake for 4-5 minutes, or until the dough becomes golden brown. 

Remove the baking sheet from the oven and transfer the layer (still on parchment paper) to a working surface. Let it cool for 1 minute, and then cut using a 18 cm/ 7 inches cake ring (or a plate of a similar size).

Place the layer onto a cooling rack and store leftovers in the airtight container until needed.

Repeat baking steps with the remaining dough.

Place cold sour cream into the bowl of stand mixer fitted with a whisk attachment.

Sift powdered sugar on top and whisk on a medium speed for 5 minutes.

(The cream can liquify at first, but keep whisking and it will come together!)

Add 1 tsp of lemon juice to the bowl, increase the speed of the mixer and whisk for another minute.

When the layers cooled down, start assembling the cake.

Place the first layer on the plate. Put about 2-3 generous tbsp of the cream in the center and distribute it evenly using the back of the spoon. Place the second layer on top and slightly press with the fingers.

Continue the process alternating cake layers and cream. You’ll have some cream leftovers to use on top and sides later. 

When the last layer is placed, gently press the whole cake with fingers. Cover the cake with a plastic wrap and place it in the fridge overnight.

In the morning, unwrap the cake. Add the remaining cream to the top and sides and smooth it with the offset spatula. 

Place the layers leftovers into a food processor and grind them into crumbs (or place leftovers into in a ziploc bag and crush them using a rolling pin). 

Decorate the top and sides of the cake with crumbs.