Ohhhhhhh, lawd. This was something I decided last minute to make due to the fact that I happened to have all the ingredients already.... I even made the vanilla pudding from scratch as well. OMG. This was definitely drool-worthy.
In a medium saucepan, off heat, whisk together sugar, cornstarch, and salt.
Very gradually whisk in milk, making sure to dissolve cornstarch.
Whisk in egg yolks.
Whisking constantly, cook over medium heat until the first large bubble forms and sputters. Reduce heat to low; still whisking, cook 1 minute, then remove from heat and dump in the butter and vanilla and mix well......
Place plastic wrap or wax paper directly on surface of pudding (to prevent skin from forming) and chill at least 3 hours before you add it to the cake....
Preheat oven to 350 degrees. Butter and flour a 9-inch round cake pan. In a small bowl, whisk together flour, baking powder, and salt; set aside.
Combine milk and butter in a small saucepan; set over very low heat.
With an electric mixer, beat eggs and sugar on high speed until thick, lightened in color, and mixture holds a trail for several seconds when beater is lifted, 4 to 5 minutes.
Gradually whisk in dry ingredients just until incorporated.
Bring milk and butter to a boil. With mixer on low speed, add hot milk mixture to batter; mix just until smooth. Mix in vanilla; transfer batter to prepared pan, and smooth top. (I forgot to take pics of this part, so enjoy my eggshells and lovely new kitchen for a moment...)
Bake until golden and pulling away from sides of pan, 35 to 40 minutes. Cool cake 10 minutes in pan; remove from pan, and transfer to a rack to cool, right side up.
With a serrated knife, split cooled cake horizontally (leave top half on rack).
Spread bottom half with only about half of the vanilla pudding within 1/2 inch of edge; gently place top half of cake on pudding layer.
Now, make the chocolate glaze.....
In a small saucepan, bring heavy cream to a boil. Remove from heat, and add chocolate; stir until smooth. Let glaze cool to room temperature and thicken slightly, about 10 minutes. When glaze has thickened, pour over filled cake. Let set for about 20 minutes and then enjoy!