Preheat the oven to 350 degrees. Prepare an 8 by 8 inch baking pan.
In a separate bowl, mix melted butter, brown sugar, flour, oats, and baking soda. Press half of the mixture into the bottom of an 8 by 8 inch baking pan.
Bake at 350 degrees for 10 minutes, then remove the pan from the oven.
Spread the 2 cups of strawberries on top of the oat mixture, then sprinkle cornstarch evenly over the top. Sprinkle lemon juice and granulated sugar over strawberries.
Crumble the remaining oat mixture and sprinkle it on top of the strawberries.
Bake for 25-30 minutes, until the crumbs looks golden.
Allow it to cool completely before cutting into bars. Makes about 12 bars depending on how large you cut them.