Step 1 In the bowl of an electric mixer fitted with a whisk attachment, beat the egg yolks and sugar on high until the mixture is very thick, pale yellow and forms a ribbon when the beater is lifted from the bowl, about 3 minutes. Remove the bowl from the mixer and sift in the cornstarch and flour, whisking to combine.
Step 2 In a medium stainless steel saucepan over high heat, begin to warm the milk. Add the vanilla bean and seeds. Bring the milk to a boil. Remove the vanilla bean. Slowly pour about one-fourth of the hot milk into the egg mixture, whisking constantly. Return the egg-milk mixture to the saucepan and combine with the remaining milk.
Step 3Cook over medium heat, whisking the mixture until it's thickened and bubbles in the center, about 6 minutes. Over a medium bowl, strain the cream through a fine mesh sieve. Cover the mixture with plastic wrap, pressing it against the surface of the cream to prevent a skin from forming. Place the bowl over ice while you prepare the filling.