Put sugar, butter, honey, and salt in a thick-bottomed saucepan. Heat the saucepan on low heat, stirring the contents.
After all ingredients in the saucepan have combined, add baking soda. A large amount of foam should appear. Keep on heat (continuing to stir) for another 2 minutes. The mass should become caramel color (but this is not required).
Add eggs to the mixture cooled to "finger-tolerable" temperature. Mix. Add flour.
Mix well again.
Divide the dough into two equal parts.
Baking the Layers
Line a 30x40cm baking sheet with parchment paper or a silicone mat. Pour the first part of the dough, spread it in an even layer. Bake in a preheated 180°C oven for 5-7 minutes.
Bake the second part of the dough in the same way.
Cut each cake in half (you'll get 4 cakes total), and cut off 1.5-2cm from each edge of each cake (these trimmings will be ground in a blender for coating).
Making the Cream
Combine sour cream and sugar. Whip with a mixer for 5-7 minutes until thickened.
Optional: Add sour cream thickener for better results - with it you don't have to worry that the sour cream cream won't whip. It also allows using sour cream with lower fat content.
Assembling
Layer the cakes with the cream between each layer.
Coat the top and sides with the remaining cream.
Sprinkle with the ground cake trimmings.
Refrigerate for several hours or overnight before serving.