Step 1: Prepare the Honey Dough. In a heatproof bowl set over a saucepan of simmering water (double boiler), combine butter, granulated sugar, and honey. Heat, stirring occasionally, until butter is melted and sugar is dissolved, about 5-7 minutes. Remove from heat. Whisk in the beaten eggs quickly to prevent scrambling. Stir in baking soda. The mixture will foam up. Gradually add 3 cups of flour, mixing until a soft, sticky dough forms. Add remaining flour as needed until the dough is manageable but still soft. Do not overmix.
Step 2: Bake the Cake Layers. Divide the dough into 8-10 equal portions. On a lightly floured parchment paper, roll out one portion into a very thin circle (about 9-10 inches in diameter). Use a plate or cake pan as a guide to trim the edges, reserving the scraps. Prick the dough all over with a fork to prevent bubbling. Bake one layer at a time in a preheated oven at 350°F (175°C) for 5-7 minutes, or until golden brown. Repeat with remaining dough portions and scraps. Let layers cool completely on a wire rack.
Step 3: Prepare the Sour Cream Frosting. In a large mixing bowl, combine very cold full-fat sour cream, very cold heavy whipping cream, powdered sugar, and vanilla extract. Beat with an electric mixer on medium-high speed until the mixture is thick, fluffy, and holds soft peaks, about 3-5 minutes. Be careful not to overbeat, or it might curdle.
Step 4: Assemble the Cake. Place one cooled cake layer on a serving plate. Spread an even layer of sour cream frosting over it, nearly to the edges. Repeat with the remaining cake layers, stacking them evenly. Frost the top and sides of the entire cake. Crumble a reserved baked cake scrap (or a fresh one, if needed) into fine crumbs and press them gently onto the top and sides of the cake for decoration.
Step 5: Chill and Serve. Cover the cake loosely with plastic wrap and refrigerate for a minimum of 12-24 hours. This chilling time is crucial for the cake layers to absorb the moisture from the frosting and become incredibly tender and moist. Slice with a sharp, warm knife and serve cold.