Heat oven to 350°F. Grease bottom only of 13x9-inch pan with shortening or cooking spray.
In large bowl, beat cake mix, water, oil and whole eggs with electric mixer on low speed 30 seconds. Beat on medium speed 2 minutes, scraping bowl occasionally. Pour batter into pan.
Bake 28 to 32 minutes or until toothpick inserted in center comes out clean. Cool completely on cooling rack, about 1 hour.
Meanwhile, in 2-quart saucepan, melt butter. Stir in sugar and egg yolks with whisk. Cook over medium heat, stirring constantly, 5 to 8 minutes or until thickened and a thermometer reads 160°F. Remove from heat. Stir in pecans, raisins, coconut and bourbon. Cool completely, about 30 minutes.
Spread custard evenly over top of cake. Garnish with cherries and whipped cream. Store covered in refrigerator.