Granola Bars

I came across a recipe for granola bars that looked to hold their shape well and decided to try them.  I've tried a few different recipes for granola bars that fall apart which is disappointing.  I modified this recipe using ingredients I had on hand.

Ingredients:
4 cups Dorset Cereal (I used simply nutty muesli kind)
1/2 cup sunflower seeds
3/4 cup chocolate chips
1 can sweetened condensed milk (300 ml)
1/4 margarine, melted

Directions:
1.  Place oven rack in center position.  Heat oven to 325F.
2.  Combine all of the ingredients mixing well.
3.  Place mixture in a parchment paper lined 15" x 10" baking sheet.
4.  Spread mixture in pan using a spatula.
5.  Bake 25-30 minutes until golden brown.
6.  Remove from oven and cool for 15 minutes.
7.  Cut into squares or bars to the size of your choice.