1. Prepare the Dough:
Combine dough ingredients in a mixing bowl and knead or mix at low-medium speed for 2-3 minutes until smooth and cohesive. Cover and let rise in a draft-free place for about 60 minutes until slightly puffy (the dough will not fully double).

2. Shape and Second Rise:
Butter one or two 8- to 9-inch round cake pans. Deflate the dough gently and divide if making two cakes. Pat or roll each portion into an 8-inch circle and place in the greased pans. Cover with plastic wrap and let rise for another 30 minutes until slightly puffed.

3. Prepare the Honey-Almond Topping:
In a saucepan over medium heat, melt cold butter with sugar, honey, heavy cream, and salt. Bring to a boil and cook for 3 to 5 minutes until the mixture lightens to a golden beige color, stirring frequently. Remove from heat and stir in the sliced almonds. Allow the mixture to cool slightly until thick but still spreadable.

4. Assemble and Bake:
Preheat oven to 350°F (177°C). Spread the almond topping evenly over the risen dough. Bake for 20 to 28 minutes, until the edges are golden and the topping bubbles and bronzes. Cool in pans for 10 to 30 minutes, then loosen edges with a knife and invert cakes onto racks. Let cool completely.

5. Make Pastry Cream:
Heat milk with vanilla in a saucepan until warm. In a separate bowl, whisk egg yolks, sugar, cornstarch, and salt until pale and smooth. Slowly add warm milk to the yolks, whisking constantly. Return mixture to the stove and cook over medium-high heat until it thickens and bubbles. Simmer gently for 1-2 minutes, then remove from heat and stir in butter. Cool completely in the refrigerator.

6. Optional Stabilized Filling:
Soften gelatin in water and melt until clear. Fold a small amount of whipped cream into the gelatin, then fold this mixture into the remaining whipped cream. Fold the stabilized whipped cream gently into the cooled pastry cream.

7. Assemble the Cake:
Once the cakes and filling are cooled, carefully slice each cake horizontally into two thin layers. Spread the pastry cream between layers, stacking carefully. Cut the almond topping layer into wedges before assembling to make slicing easier.

8. Serve and Store:
Serve immediately or refrigerate until serving. The cake is best enjoyed fresh but can be refrigerated for up to two days. Bring to room temperature before serving.