Coat a 15 x 10-inch jelly-roll pan with cooking spray; line bottom of pan with wax paper. Coat wax paper with cooking spray, and set pan aside.
Combine flour and cornstarch in a small bowl; stir well, and set aside. Combine 1/2 cup sugar, oil, 3 egg yolks, and 2 egg whites in a large bowl; beat at high speed of a mixer until thick and pale (about 5 minutes). Add vanilla; beat until blended. Add flour mixture to egg mixture, beating at low speed until blended; set aside.
Beat 4 egg whites and 1/2 teaspoon cream of tartar at high speed of a mixer until foamy. Add 1 tablespoon sugar; beat until stiff peaks form. Gently fold egg white mixture into batter; pour batter into prepared pan, spreading evenly. Bake at 450° for 6 minutes. Turn oven off.
Loosen cake from sides of pan, and turn out onto a dishtowel; carefully peel off wax paper, and let cake cool 1 minute. Starting at narrow end, roll up cake and towel together. Place, seam side down, on a wire rack, and let cool completely (about 1 hour).
Unroll cake carefully; remove towel. Brush Chocolate Syrup over cake, leaving a 1/2-inch margin around outside edges. Spread Pastry Cream over syrup, leaving a 2-inch margin around outside edges. Reroll cake; place, seam side down, on an ovenproof serving platter.
Preheat oven to 325°. Beat 4 egg whites and 1/2 teaspoon cream of tartar at high speed of a mixer until foamy. Add powdered sugar, 1 tablespoon at a time, beating until stiff peaks form. Add almond extract, and beat until blended. Spread meringue over cake roll (cake should be completely covered with meringue), and sprinkle almonds over meringue. Bake at 325° for 25 minutes. Cover loosely, and chill at least 1 hour.
Lighter Than Light version: Here's how you can lower the fat in Jolynn's Meringue Gâteau even further without sacrificing the taste.
Omit the chocolate morsels in the Chocolate Syrup, and increase the water to 3 tablespoons.
Use 1 (32-ounce) carton plain non-fat yogurt in the Pastry Cream, and use 1/8 teaspoon vanilla extract in addition to the almond extract. Increase the sugar to 1/3 cup.
CALORIES 232 (10% from fat); PROTEIN 2g; FAT 7g (sat 7g, mono 1g, poly 4g); CARB 6g; FIBER 1g; CHOL 65mg; IRON 3mg; SODIUM 89mg; CALC 130mg