Preheat oven at 325 F and butter a 10 inch pie pan

Beat egg whites until stiff, then gradually add sugar, baking powder, and vanilla

Fold in the walnuts and cracker pieces

Bake for 25 minutes at 325 F

Turn the oven off and let the pie cool in the oven for 2 hours

Topping: beat the heavy cream until stiff, then add powdered sugar and rum (optional). Garnish with chocolate curls, if desired. May use a vegetable peeler to scrape chocolate curls from a chocolate bar

Let the pie sit in the refrigerator for several hours to soften the meringue and let the flavors permeate