Gather the ingredients

Sift the flour, cornstarch, and cocoa powder together

Separate 3 eggs. Place 2 egg yolks in a small bowl, and 3 egg whites in a large bowl

Break the chocolate bar into small pieces

Prepare a deep rectangular baking pan or dish and hot water for making a water bath (bain-marie)

Preheat the oven to 200°C

Lightly butter and line the bottom and sides of a 15 cm (6 inches) baking pan with parchment paper. As the pan has a removable bottom, cover it with 2 or 3 layers of aluminum foil to avoid any leakage. Place the prepared pan into a deep baking dish.

Note: I usually heat the prepared pan in the preheated oven for about 10 minutes before pouring the batter, as I found that it prevents leakage some far.

Cut the cream cheese and butter into small cubes and place them in a heatproof mixing bowl with the milk (80 ml). Make a double boiler placing the bowl on top of a pot of simmering water. When the cream cheese and butter are soft, whisk until smooth with a balloon whisk.

Remove from the double boiler and stir again until smooth. Let cool completely.

When cooled, add egg yolks, one by one, and mix until combined.

Sift in the flour mixture

and whisk until thoroughly combined.

Meanwhile, place the chocolate in a heatproof mixing bowl with the rest of the milk (50 ml). Make a double boiler placing the bowl on top of a pot of simmering water. When the chocolate is soft, whisk until smooth. Let it cool.

After cooling, add the melted chocolate to the cream cheese mixture and mix well. If the batter is smooth enough, you don’t have to strain it. Set aside until you make the meringue.

In a clean mixing bowl, whip egg whites with cream of tartar and salt until foamy for about 1 minute on medium-high speed.

Add sugar, a tablespoon at a time, while continue beating for about 2 minutes on high speed until the meringue reaches a soft peak stage and has a glossy texture.

Finally, beat on low speed for about 1 minute. Be careful not to over-whip.

First, add one-third of the meringue to the cream cheese mixture and stir them completely into the batter. This will lighten the batter and make it easier to fold the rest of the egg whites in. Next, again add about one-third of the meringue and gently fold it into the batter being careful not the deflate the whites.

Now, place all the cream cheese mixture into the bowl with the meringue and continue folding gently being careful not to deflate the whites until all of the white lumps of meringue have disappeared.

While you make the batter, place the prepared pan in the preheated oven for about 10 minutes before pouring the batter. Remove the heated pan from the oven and gently pour the batter into the pan.

Carefully pour the hot water into the baking dish about 1/3rd of the way up the pan. Bake for 5 minutes at 200°C. Then, lower the temperature to 160°C and bake for about 30 minutes. Adjust the time and temperature as needed. (see the tips)

The cake is done when the top is nicely brown and the center is firm. Turn off the oven and remove the water bath. Leave the oven door slightly open and let the cake cool for about 30 minutes in the oven.

Remove the pan from the oven and place it onto a cooling rack. Let it sit to cool. Remove the cheesecake from the pan and then remove the parchment paper.

Transfer the cake to a serving plate. You can serve it warm, after cooling or chilling it in the fridge as you like.