Spray 9x13 inch cake pan with nonstick spray, preheat oven to 350 degrees
1. Mix the dry cake mix, 1/3 cup of canola oil and 3 eggs until it looks like stiff cookie dough.
2. In a seperate bowl, add sweetened condensed milk and 1/2 stick of butter. Microwave on normal for 1 minute. Stir until smooth.
3. Spread entire contents of cake mix batter into bottom of cake pan, dump the drained pineapple and smooth out to edges and then pour sweetened condensed milk/butter mixture over and spread to the edges. Bake in 350 degree oven for 25 minutes. Middle will seem a little jiggly. Remove, cool and cut into squares. Enjoy!