Preheat oven to 350 degrees and spray 10 inch cast iron skillet with non-stick cooking spray. In medium bowl, mix together oats, pecans, kernels, brown sugar, cinnamon, salt and flour. Cut stick of margarine into oats mixture until crumbly and mixture just holds together when pressed between the fingers. Put in the fridge to chill for 5 minutes. Meanwhile, gently rinse berries in cold water, drain well. Toss lightly with 1 Tbsp sugar and pour into prepared dish. Crumble oats mixture evenly over berries. Bake, uncovered for 25 minutes or until top is golden brown and berries are bubbly. Remove from oven and cool slightly before serving.