Combine the bread crumbs and melted butter and press on the bottom and sides of a buttered 9-inch spring-form pan. Bake for 8 to 12 minutes, or until very lightly browned. Set aside to cool.
Cook the spinach according to package directions, place in a strainer, and press out all the liquid. In a large bowl, beat together the cream cheese, cream, salt, and mustard until smooth. Add the eggs, one at a time, and beat well after each addition. Add the spinach, grated cheeses, paprika, cayenne, and scallions. Beat on low speed until well combined.
Pour the mixture into the prepared crust and bake for approximately 1 hour and 5 minutes, or until the filling is set and browned. Cool for 15 minutes on a wire rack. Serve with sliced fresh fruit and a green salad with vinaigrette dressing.