First Step: Prepare Dough and Preheat Oven Begin by greasing an 8-inch cake pan with cooking spray or butter and lining it with parchment paper to prevent sticking. Preheat your oven to 350°F (175°C). In a small saucepan, gently warm 1/4 cup (60 ml) whole milk with 4 tablespoons (57 g) unsalted butter until the butter fully melts and the mixture is lukewarm this activates the yeast later.

Second Step: Mix and Knead Dough In a mixing bowl, combine the warm milk-butter mixture with 2 large eggs and whisk thoroughly. Add 1 cup (120 g) all-purpose flour, 1 cup (120 g) bread flour, 1/4 cup (50 g) granulated sugar, 1 packet (7 g) instant yeast, and 1/2 teaspoon kosher salt. Mix and knead the dough until smooth and slightly sticky, approximately 6-8 minutes by hand or 4-5 minutes using a stand mixer with a dough hook.

Third Step: First Rise Cover the dough with a kitchen towel or plastic wrap. Let it rise in a warm place for about 1 hour or until it doubles in size, creating a soft but elastic dough.

Fourth Step: Make the Pastry Cream In a saucepan, combine half of the milk (1/2 cup) with half of the sugar (2 tablespoons), 1 teaspoon vanilla bean paste (or extract), and a pinch of kosher salt. Heat gently until it simmers. In a bowl, whisk the remaining 1/2 cup milk, 2 tablespoons cornstarch, 2 egg yolks, and remaining 2 tablespoons sugar until smooth. Temper the egg mixture by slowly pouring in some hot milk while whisking vigorously. Transfer back to the saucepan and cook over medium heat, stirring continuously until thickened, about 2-3 minutes. Remove from heat, stir in 1 tablespoon unsalted butter, and strain through a fine sieve. Cover with plastic wrap pressed onto the surface and chill for at least 1 hour.

Fifth Step: Shape Dough and Prepare Topping After the dough has risen, deflate it gently and press the dough evenly into the prepared cake pan. Let it rise again for about 30 minutes. Meanwhile, prepare the almond topping by melting 4 tablespoons unsalted butter in a saucepan over medium heat. Add 3 tablespoons honey, 3 tablespoons sugar, 1/2 teaspoon vanilla paste, and a pinch of salt. Simmer for 2-3 minutes until golden and bubbling. Remove from heat and stir in 1 cup sliced almonds. Spread this mixture over the risen dough evenly.

Sixth Step: Bake the Cake Bake in the preheated oven for 30-32 minutes until the topping is golden brown and bubbly. Remove the cake and allow to cool completely, about 1 hour.

Seventh Step: Prepare Diplomat Cream Soften 3/4 teaspoon powdered gelatin in 4 teaspoons water, then warm gently until fully dissolved. Whip 3/4 cup cold heavy cream with 3 tablespoons powdered sugar to stiff peaks. Fold a small portion of whipped cream into the gelatin to temper, then carefully fold this into the chilled pastry cream, creating a stable diplomat cream.

Final Step: Assemble and Chill Carefully slice the cooled cake horizontally in half. Spread the diplomat cream evenly over the bottom layer, then gently place the top layer back on. Refrigerate for at least 1 hour to set. Serve at room temperature or slightly chilled for best flavor and texture.