Step 1

Heat oven to 350°F. Spray bottom and sides of 2 (8-inch) heart-shaped or round cake pans with baking spray with flour.

Step 2

In large bowl, beat cake mix, champagne, oil and eggs with electric mixer on low speed 30 seconds or until combined; beat 2 minutes on medium speed. Divide batter evenly between cake pans.

Step 3

Bake 30 to 35 minutes or until toothpick inserted in center comes out clean. Cool cakes in pans 15 minutes. Remove cakes from pans to cooling racks; cool completely, about 1 hour.

Step 4

Meanwhile, in large bowl, beat butter with electric mixer on medium speed until creamy. Add melted and slightly cooled white chocolate chips; beat until smooth and combined. Add powdered sugar and vanilla; beat until well combined.

Step 5

To make cake flat, cut off rounded top of 1 cake. Place cake, cut side down, on serving plate. Frost top of cake. Top with second cake, rounded side up. Frost sides and top of cake.