Sweet, sugary, buttery goodness in a pan. This recipe is from Marsee Baking Company in Portland, Oregon. When we lived in that area, we used to pick wild blackberries and I could make this delicious dessert at a very low cost. It was heaven. The original recipe called for marionberries, but they are interchangeable in this recipe. I have never tried using frozen berries for this, so I recommend fresh.