1. Preparing the Cake Layer

1. Preheat the oven to 350°F (175°C). Butter a 9-inch springform pan generously, ensuring all surfaces are well-coated. Wrap the outside of the pan with foil to prevent any potential leakage.
2. In a medium-sized bowl, sift together the cake flour, baking powder, and salt. Set aside for later use.
3. In a large mixing bowl, beat the egg yolks with an electric mixer on high speed for about 3 minutes. Gradually add ⅓ cup of sugar while mixing and continue beating until the mixture becomes thick and pale yellow—this will take around 5 minutes. Add in the vanilla extract.
4. Gradually sift the dry ingredients over the egg yolk mixture. Once combined, gently fold the sifted flour mixture into the batter. Be careful not to over-mix.
5. Stir in the melted butter into the batter until just incorporated.
6. In a separate clean bowl, whip the egg whites and cream of tartar on high speed until frothy. Slowly add the remaining 2 tablespoons of sugar, and continue beating until stiff peaks form.
7. Fold one-third of the whipped egg whites into the batter to lighten it. Then, gently fold in the rest of the egg whites, being careful not to deflate the mixture.
8. Gently spoon the batter into the prepared pan and smooth the surface. Bake for 13–15 minutes or until the cake is set but slightly springy to the touch. Remove from the oven and cool on a wire rack.

2. Creating the Cheesecake Layer

1. In a large mixing bowl, combine one package of cream cheese, ⅓ cup of sugar, and the cornstarch. Beat on low speed for 3 minutes.
2. Gradually add the remaining cream cheese and beat on high until the mixture becomes smooth.
3. Add the remaining sugar and beat in the vanilla extract. Continue mixing until well combined.
4. Add the eggs one at a time, beating the mixture well after each addition. Once all the eggs are incorporated, blend in the heavy cream until the batter is smooth and creamy.
5. Gently spoon the cheesecake mixture over the cooled cake layer.
6. Keep the foil wrapped around the pan and place the pan in a large, shallow pan filled with hot water. The water should come up to about 1 inch of the side of the springform pan.
7. Bake the cheesecake at 350°F (175°C) for 75–85 minutes, or until the center barely jiggles when you shake the pan. Once done, cool the cake on a wire rack for 1 hour. Cover with plastic wrap and refrigerate for at least 4 hours or overnight.

3. Making the Pastry Cream

1. Combine the heavy cream, pudding mix, and milk in a bowl. Beat on high speed for about 3–4 minutes until the mixture thickens to a creamy consistency.
2. Once the cheesecake is fully chilled, spread or pipe the pastry cream evenly over the top. Chill again for at least 1 hour to set the cream.

4. Preparing the Chocolate Glaze

1. Combine the chopped chocolate, corn syrup, and butter in a microwave-safe bowl. Heat in 20-second intervals, stirring after each interval, until the mixture is completely melted and smooth.
2. Allow the glaze to cool slightly, and then pour it evenly over the pastry cream layer. Smooth it out for a glossy finish.
3. Chill the cheesecake again until the chocolate glaze is set, about 30 minutes to 1 hour.