1. Preheat oven to 350°.
2. Drain pineapple, reserving juice for another use. Squeeze pineapple well using several thicknesses of paper towels to remove excess moisture.
3. Combine cake mix and next 7 ingredients in an 8-qt. mixing bowl. Beat at low speed with an electric mixer 2 minutes; beat at medium speed 3 minutes. Fold in pineapple, white chocolate, and next 3 ingredients. Pour batter into 4 greased and floured 9-inch round cake pans.
4. Bake at 350° for 34 to 36 minutes or until a wooden pick inserted in center comes out clean. Cool in pans on wire racks 10 minutes. Remove from pans to wire racks, and cool completely. Wrap and chill cake layers at least 1 hour or up to 24 hours.
5. Using a serrated knife, slice cake layers in half horizontally to make 8 layers. Place 1 layer, cut side up, on cake plate. Spread with 1/2 cup White Chocolate Cream Cheese Frosting. Repeat procedure 6 times. Place final cake layer on top of cake, cut side down. Spread remaining frosting on top and sides of cake. Cover; chill in refrigerator overnight. Garnish, if desired. Store in refrigerator.
Note: Cover cake in an airtight container and freeze up to 1 month in advance. Thaw in refrigerator overnight before serving.
To prepare a 4-layer White Chocolate Hummingbird Cake instead, use half of all ingredients in both cake and frosting recipes. Follow cake recipe as directed in Steps 1 through 4, except use only 2 greased and floured 9-inch round cake pans. In Step 5, slice the 2 cake layers in half horizontally to make 4 layers. Follow White Chocolate Cream Cheese Frosting recipe as directed except microwave white chocolate morsels in Step 1 for only 1 1/2 minutes. Assemble cake as directed. Both the 8- and 4-layer versions of this delicious cake slice best after they have chilled overnight.