Custard Filling:

2 c. heavy (whipping) cream
1 (3-inch) cinnamon stick or 1/4 tsp. ground cinnamon
1 vanilla bean, halved lengthwise or 1 tbsp. vanilla extract
1/4 c. sugar
yolks from 4 eggs

Cake:

1/4 tsp. salt
1/2 c. milk
1/2 stick (1/4 c.) cold unsalted butter, cut in pieces
2 large eggs (room temperature)
2/3 c. sugar
1 tsp. vanilla extract

Glaze:

1/4 c. heavy (whipping) cream
3 oz. best-quality semi-sweet or bittersweet chocolate, coarsely chopped

Custard Filling: Place cream and cinnamon in a small heavy saucepan. If using vanilla bean, scrape seeds into cream and add pod. Slowly bring to a boil over medium-low heat, watching closely or cream may overflow. Remove from heat and add sugar; stir until dissolved. Add vanilla extract, if using. If using cinnamon stick and vanilla bean, let steep for about 1 hour.

Heat oven to 325°F. Have ready a 9-inch ovenproof glass pie plate, a shallow baking pan large enough to hold pie plate and a 9-inch round cake pan. Bring a kettle of water to a boil. Whisk egg yolks in a medium bowl. Reheat cream mixture over medium-low heat until almost boiling. Gradually whisk (don't beat) hot cream into egg yolks. Pour into pie plate; set pie plate in baking pan. Add boiling water to come halfway up sides of pie plate.

Bake 20 to 25 minutes until tip of a sharp knife inserted in center comes out clean. Remove pie plate from water to a wire rack; cool to room temperature.

Meanwhile prepare cake: Heat oven to 350°F. Coat cake pan with nonstick spray. Line bottom of pan with wax paper; spray paper and dust pan lightly with flour. Sift flour, baking powder and salt into a medium bowl. Heat the milk and butter in a small heavy saucepan over low heat. Meanwhile, beat eggs with mixer on high speed until thickened and pale. On medium speed, beat in sugar, then beat on high 5 minutes. Beat in vanilla. On low speed, add flour mixture, beating just until blended. Scrape bowl, handling batter as gently as possible. Quickly bring milk and butter mixture to a boil. While beating batter on low speed, pour in milk mixture in a slow steady stream, taking 15 to 20 seconds to do so. Scrape into prepared cake pan.

Bake 25 to 30 minutes until cake is a deep golden brown and springs back when gently pressed.