Preheat oven to 325. In a food processor, grind 7 oz. hard, crunchy cookies into fine crumbs. Drizzle in 6 tbsp. melted butter and whirl until crumbs start to come together. Press crumb mixture firmly over bottom (not sides) of pan called for by recipe. Bake until crust is set, about 10 minutes. Let cool completely.
Note: If cookies are really buttery, start with 2 tbsp. butter and add only enough extra butter to make crumbs cling together.
Buttery Pie Pastry
Whirl together 1 cup flour, 2 tbsp. powdered sugar, and 1/4 tsp. sald in a food processor. Cut 1/2 cup cold unsalted butter into cubes. Drop into bowl and pulse until mixture looks like large cracker crumbs and flour. Whirl in 1 lightly beaten egg yolk and 1 to 2 tbsp. ice water, pulsing just until mixture comes together in a shaggy ball but you can still see bits of butter. Divide into disks (one for each pan you will use), wrap in plastic wrap and chill at least 30 minutes and up to 2 days.