Put the milk in a saucepan. Split the vanilla bean, scraping the seeds into the milk, then drop in the pot. Heat to a simmer, remove from heat, cover, and set to infuse 10 minutes.
In bowl using an electric mixer, beat the yolks with the sugar until pale. Beat in the flour. Pull the vanilla bean from the milk and whisk the milk gradually into the egg mixture. Pour back into the saucepan, bring to a boil, and cook 1 minute. Remove from the heat and stir in the framboise. Strain into a bowl, cover with plastic wrap, and set aside to cool. When chilled, whip the cream and gently fold it in.
Spread the pastry cream evenly in the base of the prepared cookie crust. Arrange the berries neatly over top.
Recipe courtesy of Laura Calder