Preheat oven to 350°.
To prepare cake, coat 2 (8-inch) round cake pan with cooking spray; line bottom of pans with wax paper. Coat wax paper with cooking spray; set aside.
Lightly spoon cake flour into dry measuring cups; level with a knife. Combine cake flour, 1/2 cup sugar, and baking powder in a large bowl; stir with a whisk. Add walnut meal; make a well in center of mixture. Combine 1/2 cup syrup, oil, and vanilla. Add to flour mixture; beat with a mixer at medium speed until blended.
Beat salt and egg whites with a mixer at high speed until soft peaks form using clean, dry beaters. Gradually add remaining 1/4 cup sugar, 1 tablespoon at a time, beating until stiff peaks form. Gently stir one-fourth of egg white mixture into flour mixture; gently fold in remaining egg white mixture. Spoon into prepared pans. Bake at 350° for 20 minutes or until a wooden pick inserted in center comes out clean. Cool for 5 minutes in pans on wire racks. Remove from pans; peel off waxed paper. Cool completely on wire racks.
To prepare maple cream, combine 2/3 cup syrup and the next 3 ingredients (through dash of salt) in a small saucepan, and stir until smooth. Bring to a boil over medium heat, and cook for 1 minute. Remove from heat. Cover and chill. Gently fold in whipped topping. Refrigerate 1 hour.
Place 1 cake layer on a plate; spread with 1 cup maple cream. Top with remaining cake layer. Spread remaining maple cream over top and sides of cake. Arrange walnut halves on top. Store cake loosely covered in refrigerator.