In a medium bowl, combine the oats, brown sugar, flour, butter, cinnamon and salt. Mix by hand with a wooden spoon until the mixture resembles clumps of sand. Spread the crumble over the parchment paper and bake for 8 to 10 minutes, stirring halfway through. The crumble should be golden brown. Let it cool completely and then crumble the mixture into smaller pieces, if needed.