1. Preheat the oven to 350 degrees F. Line baking dish with parchment paper.
2. In the bowl or a food processor, pulse together the oats, flour,brown sugar, baking powder and cinnamon, until the oats are mostly grounded. Add the cold butter pulse until a crumbly dough forms. If the dough seems dry, add 1 tablespoon water.
3. Press 1/3 of the dough into the bottom of the prepared baking dish. Transfer to the oven and bake 10 minutes or until lightly golden.
4. Spoon the jam out into an even layer over the pre-baked crust. Sprinkle the remaining crumble dough overtop the jam mixture. Return to the oven and bake for 30-40 minutes or until the crumble is a light golden brown and the jam burst.
5. Let cool completely before cutting into bars. Keep stored in a sealed container for up to 1 week.