To make the filling, in a medium, heat-proof mixing bowl, whisk together the sugar, cornstarch, and salt.

Add the egg yolks and whisk until the mixture is pale and smooth, about 1 minute. The mixture will seem too dry at first but keep whisking and it will loosen. Whisk in the milk, a splash at a time, whisking constantly until all of the milk has been incorporated.

Pour the milk mixture into the saucepan and cook over medium-low heat, whisking constantly, until the custard begins to simmer and thickens, about 5 minutes.
Once it begins to gently bubble, continue to cook, stirring constantly, for 1 minute longer to cook out the starch. Take the pan off the heat and whisk in the vanilla extract.

Pour the pastry cream through a fine-mesh strainer into a clean bowl and cover with plastic wrap directly on the surface of the pastry cream. Refrigerate while preparing the cake.

To make the cake, heat the milk and the butter in a small saucepan over low heat until the butter melts. Take the pan off the heat and let the mixture sit until lukewarm.

Pour the milk and butter into the bowl of a stand mixer fitted with a dough hook. Add the honey, eggs, bread flour, yeast, and salt. Mix on low speed for about 1 minute until everything comes together and forms a rough dough. Then, increase the speed to level 2/medium speed and continue kneading for 6 minutes. The dough should be smooth and elastic and not sticky.

Transfer the dough to a lightly greased mixing bowl. Cover and let it rise in a warm spot until the dough has doubled in size, about 1 hour.

While the dough is rising, make the almond topping. Place the butter, honey, and sugar in a small, heavy-bottomed saucepan. Set it on medium heat and cook until the sugar dissolves and the mixture begins to bubble. Remove from the heat and stir in the sliced almonds. Set aside and let it cool.

Grease a 9-inch springform pan lightly with butter. Dust the bottom and sides with flour and tap out the excess.

Punch down the dough. Transfer it to the prepared springform pan and gently press and stretch to evenly fill the pan. Gently spread the almond topping over the dough to cover the entire surface.

Cover the pan and let the cake rise in a warm spot until doubled, about 30 minutes (depends on room temperature).

About 20 minutes before the cake is ready to bake, set a rack in the center of the oven. Preheat the oven to 350°F/190°C.

Bake the cake for 25 to 30 minutes, or until the edges are golden and the topping is bubbling.

Remove the cake from the oven and let it cool in the pan for 20 minutes to allow the topping to firm up. Then, run a knife around the edges of the pan to loosen the cake from the pan and place it on a wire rack to cool completely before filling.

In the bowl of a stand mixer fitted with the whisk attachment, or a large mixing bowl if using a hand mixer, beat the heavy whipping cream on medium-high speed until stiff peaks form, 1 to 2 minutes. The cream should thicken and when you pull the whisk out of the bowl, the peak should stand up.

Remove the pastry cream from the refrigerator, and use a whisk to stir the pastry cream until smooth and creamy. Add half of the whipped cream to the chilled pastry cream and use a rubber spatula to gently combine. Then fold in the rest of the whipped cream. The filling should be smooth, light, and airy.

Once the cake has cooled completely, assemble the cake. Using a serrated bread knife, split the cake in half horizontally. Use a spatula to spread the filling over the bottom layer of the cake. Leave a half-inch margin around the edges. You won't use all of the filling, or it may ooze out the sides.

Place the top layer over the filling. While you can serve it right away, letting it chill for a couple of hours before serving helps set the cake for easier slicing.

Store the cake, covered, in the refrigerator for up to 2 days. I don’t recommend freezing this cake as pastry cream with cornstarch doesn’t freeze and thaw well.