Put the pear slices in a
Put the pear mixture in a food processor fitted with the metal blade and purée. Pour the purée into a heavy-bottomed saucepot. Cook, stirring often, for about 10 to 15 minutes, until thick. Refrigerate the purée until it is cold.
Butter and sugar the soufflé dish.
Put the egg whites in the bowl of an electric mixer. Using the whisk attachment, whip them on medium speed until frothy. Increase to high speed, add the cream of tartar, and whip until soft peaks form. Continue whipping and slowly add the remaining
Fold the pear purée into the egg whites. Do not completely incorporate; the soufflé batter should still have slight streaks of pear purée. Carefully spread the batter in the prepared dish. Tap the dish gently on the counter and swirl the top with your finger, making a slight peak in the middle of the soufflé.
Dust the top of the soufflé with the powdered sugar and serve it immediately with the ollalieberry sauce on the side.