Combine butter and brown sugar in (8x8 inch) baking dish. Microwave 1- half to 2 minutes on HIGH, or until butter and sugar melt. Stir. Arrange pineapple and cherries in syrup.

Blend cake mix, pineapple juice and eggs in medium mixing bowl on low speed of electric mixer. Beat on medium speed for two minutes. Pour evenly over fruit. Micro 8- half to 10 minutes on HIGH, or until wooden pick inserted in center comes out clean. (Rotate dish half turn after 5 minutes) Immediately invert onto serving plate and remove dish. Cool