Combine flour, oats and sugar, cut in butter using a pastry cutter or 2 knives until mixture resembles coarse meal. Set aside.
Peel, core and cut the apples into 1/8 pieces. Melt butter in a large skillet. Add the apples and cinnamon and cook for 8-10 min or until slightly tender.
Preheat oven to 400º. Butter a 10x13” casserole dish or baking pan.
In a medium bowl combine eggs, and sugar and whisk until smooth. Add the cream and vanilla, mix to combine. Place the cooked apples in the prepared baking dish. Spread evenly. Pour the creamed mixture over the top. Evenly sprinkle the crumb topping over the cream and apples. Bake for 30-35 min or until golden brown.