vanilla or white chocolate chips
Preheat oven to 350 deg. Line a 9x9 pan with foil & spray with no-stick spray. Beat butter with mixer till smooth. Add egg & beat. Add cake mix. Batter will be crumbly.
Press 2/3 into pat sprinkle with chips & drizzle with condensed milk. Break up remaining dough & crumble over milk. Press to seal.
Bake for 28-38 min or till light brown. Cool and cut.