Preparation Preheat oven to 350°F. On a baking sheet in middle of oven toast almonds in one layer until golden, about 10 minutes. Peel, quarter, and core quinces. Cut each quarter lengthwise into 5 slices. In a 3-quart heavy saucepan bring water and sugar to a boil, stirring until sugar is dissolved. Add quince and simmer, covered, 2 1/4 hours. When mixture has been simmering 2 hours, peel, quarter, and core apples. Cut each quarter lengthwise into 1/4-inch-thick wedges. Stir apples into quince mixture and simmer, covered, until apples are crisp-tender, about 10 minutes. Remove pan from heat and stir in almonds and extract. Cool filling. (Filling may be made 3 days ahead and chilled, covered.) Assemble jalousie: In a large sieve set over a bowl drain quince filling, reserving syrup. Transfer quince to a bowl and stir in 3 tablespoons reserved syrup. Make an egg wash by lightly beating egg with 2 teaspoons water. Halve dough and on a lightly floured surface roll out each half into a 12- by 8-inch rectangle (about 1/4 inch thick). Transfer 1 pastry rectangle to a floured large baking sheet and put quince filling lengthwise along center, forming a 9- by 5-inch mound. Brush pastry around filling with some egg wash. Carefully drape remaining pastry rectangle lengthwise over quince and seal edges by gently pressing together. With a sharp large knife trim edges of pastry. Crimp edges and make a decorative pattern of about 8 slits in pastry, exposing filling. Chill jalousie, loosely covered, 30 minutes. Preheat oven to 425°F. Brush jalousie evenly with some egg wash and sprinkle with sugar. Bake jalousie in middle of oven until deep golden, about 30 minutes, and transfer on pan to a rack to cool. Serve jalousie warm or at room temperature with remaining reserved syrup and whipped cream.
Preparation Preheat oven to 350°F. On a baking sheet in middle of oven toast almonds in one layer until golden, about 10 minutes. Peel, quarter, and core quinces. Cut each quarter lengthwise into 5 slices. In a 3-quart heavy saucepan bring water and sugar to a boil, stirring until sugar is dissolved. Add quince and simmer, covered, 2 1/4 hours. When mixture has been simmering 2 hours, peel, quarter, and core apples. Cut each quarter lengthwise into 1/4-inch-thick wedges. Stir apples into quince mixture and simmer, covered, until apples are crisp-tender, about 10 minutes. Remove pan from heat and stir in almonds and extract. Cool filling. (Filling may be made 3 days ahead and chilled, covered.) Assemble jalousie: In a large sieve set over a bowl drain quince filling, reserving syrup. Transfer quince to a bowl and stir in 3 tablespoons reserved syrup. Make an egg wash by lightly beating egg with 2 teaspoons water. Halve dough and on a lightly floured surface roll out each half into a 12- by 8-inch rectangle (about 1/4 inch thick). Transfer 1 pastry rectangle to a floured large baking sheet and put quince filling lengthwise along center, forming a 9- by 5-inch mound. Brush pastry around filling with some egg wash. Carefully drape remaining pastry rectangle lengthwise over quince and seal edges by gently pressing together. With a sharp large knife trim edges of pastry. Crimp edges and make a decorative pattern of about 8 slits in pastry, exposing filling. Chill jalousie, loosely covered, 30 minutes. Preheat oven to 425°F. Brush jalousie evenly with some egg wash and sprinkle with sugar. Bake jalousie in middle of oven until deep golden, about 30 minutes, and transfer on pan to a rack to cool. Serve jalousie warm or at room temperature with remaining reserved syrup and whipped cream.