One of Jacques P?pin's all-time favorite desserts, raspberry gratin, is a cinch to make if you have frozen, unsweetened raspberries on hand, as he always does, and good-quality store-bought cookies. P?pin gives two recipe variations: One is made with packaged chocolate-chip cookies, because he loves the combined flavors of chocolate and raspberries; and one makes use of buttery shortbread, his wife's favorite recipe.
The chocolate-chip cookies are best crumbled by hand, because the chips would puree in a food processor and make the mixture pasty. The shortbread can be crumbled in the food processor or by placing it in a plastic bag and crushing it with the bottom of a small skillet or a rolling pin. The gratins are best served lukewarm or at room temperature, with or without sour cream.