Melt the butter in the microwave.
In a large bowl, combine all of the ingredients except the jam. Mix with your hands until the ingredients are crumbly, taking care to break up all clumps of the cake mix.
In a 13" x 9" shallow baking pan, such as a cookie sheet, press 1/2 of the oatmeal/cake mixture in the pan. Make sure to keep the layer as even as possible.
Pour the jam into a bowl and mix well. This helps the jam to spread easier. Spread the jam onto the first oatmeal layer.
Press the remaining oatmeal/cake mixture onto the top of the jam. Try to keep layers as even as possible.
Bake for 40-50 minutes or until oatmeal is lightly browned. Cut into bars once cooled.
Optional Glaze: Add water to powdered sugar into is is a pourable mix, about 3-4 teaspoons. Lightly drizzle over the pan. Cut into bars once cooled.