Cream Filling
Soften the butter and beat together with the condensed milk. Mix in just enough sour cream to ensure the mixture still remains reasonably thick but easy to spread. Don't worry if it gets a bit runny, much of the cream filling will eventually get soaked up by the layers of cake, but might take a bit longer.

Chill the cream filling while you prepare the cake.

Cake
Beat the eggs until combined. Gradually mix in 1.5 - 2 cups of the flour.

In a saucepan gently heat together the honey, sugar and butter. Add the baking soda, stir together until foaming. Turn off the heat.

Add the honey mixture to the dough. Stir to combine. Gradually add in more flour, half a cup at a time until the dough comes away from the sides of the mixing bowl.

Transfer the dough to a lightly floured surface and knead for a minute or two until smooth, then divide into 8 equal portions.

Roll out each portion until it is 20cms in diameter and 1-2mm thick. Place each round onto a greased flat baking tray and prick the surface all over with a fork.

Heat the oven to 180 degrees C. Bake each layer of dough for 4-5 minutes until lightly cooked - the texture of soft cake rather than hard biscuit. Remove layers from the baking trays and cool.

Assembly
Using the loose base of the baking tin as a cutting guide, trim the edges off each baked layer to create 8 equally sized rounds. Keep the trimmings as they will be used for the topping.

Place the loose bottom back into the baking tin and put one baked layer of cake into the bottom of the tin. Spread 1/8th of the cream filling over the layer of cake. Repeat with the remaining layers, topping with the last portion of filling.

Crumble the leftover cake trimmings in a food processor until they become fine crumbs. Sprinkle 1/3 to 1/2 of the crumbs over the last layer of filling on the top of the cake. Reserve the remainder to coat the sides after the cake has been removed from the tin.

Refrigerate the cake for 12 - 24+ hours, until the filling has solidified and been partly absorbed by the layers of cake.

Serving
Run a clean knife around the inside of the baking tin and ease the cake out of the tin. Coat the sides with the remaining cake crumbs. Slice and serve.