Step 1: Prepare the Yeasted Dough
In a small bowl, dissolve the yeast and 1 teaspoon of sugar in warm milk. Let it sit for 5-10 minutes until foamy.
In a large mixing bowl, combine flour, remaining sugar, and salt. Add the yeast mixture, egg, softened butter, and vanilla extract.
Knead the dough for 5-7 minutes until smooth. If sticky, add a little flour.
Cover the bowl with a cloth and let the dough rise for 1 hour, or until doubled in size.
Step 2: Make the Honey-Almond Topping
In a small saucepan, melt the butter over medium heat. Stir in sugar, honey, and heavy cream, and cook for 2-3 minutes until slightly thickened.
Add sliced almonds, stir, and let cool while you prepare the cake.
Step 3: Bake the Cake
Preheat the oven to 350°F (175°C). Grease a 9-inch round cake pan.
Punch down the risen dough and place it into the prepared cake pan. Spread evenly.
Carefully spoon the honey-almond mixture over the dough.
Bake for 20-25 minutes, until the top is golden brown and caramelized. Allow to cool completely.
Step 4: Prepare the Custard Filling
In a saucepan, heat milk over medium heat until warm.
In a bowl, whisk together egg yolk, sugar, and cornstarch until smooth.
Slowly pour the warm milk into the egg mixture, whisking constantly.
Return the mixture to the saucepan and cook over low heat, stirring, until thickened (about 5 minutes).
Remove from heat, stir in vanilla extract, and let cool. For a lighter texture, fold in whipped cream.
Step 5: Assemble the Cake
Once the cake is cool, carefully slice it horizontally into two layers.
Spread the custard filling evenly over the bottom layer.
Place the top layer back on and refrigerate for 1 hour before slicing and serving.