Preheat oven to 350 degrees F. Line a 9x13" rectangular baking pan with foil, extending the edges of the foil over the sides of the pan. Spray the foil liberally with cooking spray. Set aside.

In a large bowl, combine the cake mix, butter (or oil), and egg and mix well until a soft dough forms. Press the dough into the prepared baking pan in an even layer. Bake for 12 minutes. Remove from oven, but keep oven on.

Top the partially-baked crust with the coconut, chopped pecans, white chocolate chips and Cadbury mini eggs. Drizzle the top with the sweetened condensed milk. Return to the oven and bake for 18-20 minutes or until the top is lightly golden brown and the center appears set. If it jiggles slightly, that is okay - but it should not be sloshing around in the pan. Cool completely, then let set for 1-2 hours before cutting into squares.