Position a rack in the center of the oven and heat the oven to 350°F

Place the crackers in the bowl of a food processor and process until fine crumbs form. Add the salt, sugar and melted butter and process again until well combined.

Place the crumbs into the tart pan and evenly spread the crumbs so that they cover the bottom of the pan and sides. Press down on the bottom firmly to make a compact layer. Use your fingers to pinch and press some of the crumbs around the inside edge of the pan to cover the sides evenly and create a rim about a ¼ inch thick. Bake the crust until it’s golden brown and smells nutty, about 10 minutes. Set the baked crust on a rack and let cool. Note: The crust can be made up to a day ahead and stored at room temperature, wrapped well in plastic.

Add milk, 1/3 cup of sugar, salt, scraped vanilla seeds, and the pod to a medium saucepan. Bring to a simmer over medium/high heat, but don’t let it boil. Turn off the heat and let sit for 15 minutes while the vanilla infuses. (if using extract, no need to let it sit. Add it later).

In a medium bowl, whisk together the egg yolks, cornstarch and remaining 1/4 cup sugar until fully combined.

Once the milk has infused, remove the vanilla pod* and bring mixture back up to a simmer. When it’s ready, turn off the heat and, while whisking, slowly drizzle in about half the milk to the egg yolk mixture (this tempers the yolks so they don't turn into scrambled eggs). Then, while whisking, pour the tempered yolk mixture back into the saucepan and cook over low heat, stirring constantly with a wooden spoon, until the mixture thickens, 5 to 7 minutes. Don't worry if the custard looks like it’s curdled when it comes to a boil; just switch to a whisk and beat vigorously. Cook, whisking constantly, for another 2 minutes; the custard will come together and become very thick, like pudding.

Remove from heat and whisk in butter and vanilla. If there are any lumps, strain the pastry cream into a bowl through a fine mesh sieve or strainer. Press a layer of plastic wrap directly on to the surface and refrigerate until cold and set, at least 3 hours or up to 2 days.

*Don’t throw away scraped vanilla pods. Rinse them well and let them fully dry. Then add to a jar of sugar to make vanilla sugar. Keep adding pods as you use them

Using a hand whisk or a stand mixer with the paddle attachment, whisk 3 cups of cold pastry cream until it’s light and very smooth, 1-2 minutes. Pour into cooled tart shell and top with berries and mint sprigs, as desired. Can be refrigerated for up to a day before serving (add fruit just before serving). To get a shiny look on the berries, brush them with a little jam thinned with hot water.