Alan S Pumpkin Pie
¼ cup pasteurized egg whites ¼ cup water ½ cup sugar 1 cup whipping cream 1 8 ounce carton mascarpone cheese 2 tablespoon Frangelico or other hazelnut liqueur (optional) ⅓ cup hazelnuts Alan’s Pie Pastry 3 ¾ cup all-purpose flour 1 tablespoon sugar ½ tablespoon kosher salt ½ teaspoon baking powder 1 ¾ cup unsalted butter ⅔ cup ice-cold water 2 tablespoon sour cream 1 teaspoon vinegar