Spread 3 ounces melted chocolate in a 9-inch graham cracker crust; chill until set. Cook 12 ounces pitted cherries with 3 tablespoons sugar, 1 tablespoon butter and 1 teaspoon vanilla in a skillet over medium heat until tender, 5 minutes. Whisk 1 tablespoon cornstarch and 3 tablespoons water; stir into the cherries and cook until thickened, 3 minutes. Let cool, then pour into the crust. Puree 1 cup ricotta, 1/2 cup each pistachios, cream cheese and confectioners' sugar, 1 teaspoon vanilla and 1/4 teaspoon almond extract; spread over the cherries. Top with chopped pistachios and candied orange peel. Refrigerate until set, about 1 hour.