For the Butter Cake Layer:
Preheat oven to 350°. Line a 9x13-inch baking pan with foil and spray with non stick cooking spray.
In a medium bowl stir together the cake mix, eggs and oil, until combined. Press dough into prepared baking pan. Bake 18 minutes or until the edges are baking and the center is slightly under baked. Set aside to cool (about 25 minutes).
For the Pineapple Fudge:
Add freeze dried pineapple to a blender. Blend until the pineapple is a fine powder (some pieces are fine). In a 4 cup microwave safe bowl, mix white chocolate chips, sweetened condensed milk, butter and food coloring. Stir until combined. Microwave 1 minute. Stir until creamy. Add the freeze dried pineapple, pineapple flavor and stir to combine. Pour on top of the baked cake layer, use an offset spatula to smooth the fudge. For a quick hardening process cover and place fudge in the refrigerator or let the fudge sit on the counter (covered).