Place the pie in the oven and bake for 50-55 minutes.
After 15 minutes of baking, put the foil ring over the pie.
After 35 minutes of baking, spread the crumble over the whole pie, put the foil ring back on the pie and return to the oven. It is critical to add crumble in the last 15-20 min of baking. Longer baking will make the crumble taste bitter.