Put the egg yolks into a bowl. Mix on medium-low for about 30 seconds.
Reduce the speed and pour in the sugar and salt, bringing it back up after it has been added. Continue to mix until the yolks lighten in color and the mixture starts to thicken. When the whisk is lifted, the mixture should form a slowly dissolving ribbon.
Scrape down the sides of your bowl and add your cornstarch mixing again until thoroughly incorporated.
Keeping the mixer running pour in your milk.
When everything has been mixed completely, transfer all this into a large, heavy-bottomed saucepan and set over medium heat.
Using a whisk, stir constantly until the mixture reaches the consistency of thick pudding and loses all traces of the cornstarch flavor, roughly 10 minutes.
Pour the cream through the strainer immediately. Whisk in the butter, vanilla, and rum, whisking until the butter has completely melted and everything is thoroughly combined.
Transfer into a container and press a piece of plastic wrap directly against the surface of the cream.
Refrigerate until firm about 1 hour.
Adjust the oven rack to the lower-middle position and bring the oven temperature up to 350℉.
Grease two 9-inch cake pans and cover the bottoms with parchment paper.
Whisk flours, baking powder, and salt in a medium bowl.
Heat the milk and butter in a small saucepan over low heat until the butter melts. Remove from the burner and set aside covering the pan to keep warm.
Separate three of the eggs, place the whites in the bowl and using a standing mixer or a high sided bowl and a hand mixer beat the whites until foamy.
Increasing speed to med-high, gradually adding in six tablespoons of the sugar; continue to beat the whites until they hold soft peaks.
In another large bowl whisk the remaining three yolks and two whole eggs with the rest of the sugar. Beat until the eggs lighten in color and become very thick. Add the beaten eggs to the whites.
Sprinkle the flour mixture over the eggs and fold gently. Before all traces of flour and egg white are completely gone, grab the saucepan of milk and butter and pour it into one side of the mixture being careful not to deflate the whites. Continue to fold until everything is evenly distributed.
Pour the batter into your prepared cake pans immediately, and bake until the tops of the cake are light brown and spring back when touched. This should take roughly 16 minutes.
When the cakes are done immediately run a knife around the edges to separate the cake and invert the pan onto a large plate. Peel off your parchment paper and invert again onto a cooling rack. Do this with both cakes, allowing them to cool to at least room temperature before assembly.
Bring the corn syrup and cream to a simmer in a heavy-bottomed pan, stirring occasionally to prevent any scorching of the cream.
Remove from the heat and add the chocolate, cover for five minutes, until the chocolate gets melty.
Add the vanilla stirring until the mixture is smooth.
Cool till the chocolate thickens.
While the glaze is cooling, place one cake layer on a cardboard round over a cooling rack.
Spread all the pastry cream onto the first layer, once the cream is evenly distributed top with the second layer of cake.
Pour the glaze over the middle of the top of the cake letting it flow down the sides for a drip effect, or smooth the chocolate around the sides covering the whole cake evenly.
If there are any air bubbles in the glaze pop them now with a small needle.
Let sit until the glaze fully sets about an hour. Then serve!