01 -
In a medium saucepan set over medium heat, combine cranberries, granulated sugar, lemon juice, cornstarch, and vanilla extract. Cook for 5 to 7 minutes, stirring occasionally, until the cranberries begin to burst and the mixture thickens. Remove from the heat and allow to cool.
02 -
In a large mixing bowl, whisk together flour, rolled oats, brown sugar, baking powder, and salt. Add melted butter and stir until the mixture forms coarse crumbs.
03 -
Preheat oven to 175°C. Line a 20x20 cm baking dish with parchment paper, leaving an overhang for easy removal. Firmly press half of the crumble mixture into the base of the dish to create an even crust. Spread the cooled cranberry filling evenly on top, then scatter the remaining crumble mixture over the filling.
04 -
Bake in the centre of the preheated oven for 40 to 50 minutes until the topping is golden brown and the filling bubbles at the edges. Remove from the oven and let cool in the pan for 30 minutes.
05 -
Using the parchment overhang, lift the cooled slab out of the dish. Cut into squares or rectangles. Serve plain or lightly dusted with powdered sugar if desired.