Bake the cake ahead of time. Store at room temperature up to three days, or place it in a large zip-top plastic freezer bag, and store in the freezer up to one month. Let thaw; then top with icing and sprinkles.
Beat butter at medium speed with an electric mixer until creamy. Gradually add sugars, beating at medium speed until light and fluffy. Add eggs, 1 at a time, beating just until yellow disappears after each addition.
Stir together flour, salt, and baking soda. Add to butter mixture alternately with sour cream, beginning and ending with flour mixture. Beat at low speed just until blended after each addition. Stir in vanilla. Pour into 2 greased and floured 9- x 5-inch loaf pans.
Bake at 325° for 1 hour to 1 hour and 10 minutes or until a wooden pick inserted in center comes out clean. Cool in pans on a wire rack 10 minutes. Remove cakes from pans, and let cool 2 hours or until completely cool.
Prepare Caramel Icing, and pour over cake, allowing it to drip down sides of cake. Top with Apricot-Ginger Sprinkles; let stand 30 minutes or until icing is firm.