Preheat the oven to 350F/180C.
Make the crust by whisking together the crumbs and the sugar, then pour in the melted butter and thoroughly combine. Press them evenly into the pie tin. Refrigerate for at least a half-hour before using. To make the crumbs, I buy cheap butter cookies, break them up, and toss them in the blender.
For the custard filling, whisk together the sugar and flour in a bowl, then add the cream and egg, and whisk the whole mixture until thoroughly combined.
For the berries, mix them with the sugar and salt in a separate bowl. NOTE: I've used frozen berries for this recipe plenty of times and they work just fine but just be sure to defrost them first. Also, if using a smaller tin, use fewer berries, naturally.
Spoon the berries into the crust, then pour in the custard mix. Like I said, I used a smaller tin so I had some custard mix leftover. Meh, I'll live.
Cook on the center rack for 45 minutes or so. The center should be a bit wobbly still (if making a smaller size, start checking on it after 40 minutes). Take it out of the oven, let it cool completely on a wire rack, and then refrigerate for at least two hours before serving.