Preheat oven to 350°F. Lightly spray pan with vegetable pan spray.
In small bowl, stir together flour, walnuts, baking soda and salt. In large bowl, beat butter and sugar with electric mixer until light and fluffy. Add eggs, one at a time; add vanilla and beat thoroughly. Add flour mixture alternately with sour cream; beat well. Pour batter into prepared pan, filling cavities 2/3 full.
Bake 12-15 minutes or until toothpick inserted in center of cakes comes out clean. Cool in pan on cooling rack 5 minutes; remove from pan and cool completely before glazing.
In small bowl, stir together sour cream, confectioners? sugar, and vanilla extract until well combined. Dip tops of cooled cakes into glaze; sprinkle with nuts and Sparkling Sugar.