Preheat oven 350.

To prepare crumb crust/topping, spread nuts in baking pan and roast, stirring occasionally, till toasted, about 10 minutes. Remove nuts from oven, turn out onto a cloth towel and rub off and discard papery skins.

Increase oven temp to 450.

In food processor fitted w/metal blade, process nuts until finely ground, about 10 seconds.

In large bowl, mix together nuts, flour and sugar. Using a pastry blender or 2 knives, cut the butter into the flour mixture until coarse crumbs form. Using fingers, evenly press half the crumb crust/topping mixture into the bottom and sides of an 8-or 9-inch tart pan.

To prepare the filling, in a medium bowl, mix together the sugar and cornstarch. Gently fold in the berries.

Spoon the berry mixture into the crust, spreading evenly.

Sprinkle the berry mixture evenly with the remaining crumb crust/topping.

Bake until topping is golden and filling is bubbly, 30 minutes. Transfer the pan to a wire rack to cool for 10 min. Serve warm.