Bring a large saucepan of lightly salted water to a boil. Add lasagne noodles and cook until tender; about 8 minutes. Drain and rinse noodles then set aside.
In a medium bowl mix together the Cheddar cheese, ricotta cheese, egg, white sugar and almond essence.
Spread half the apple pie filling in the bottom of a 20x30cm baking dish. Layer half of the noodles to cover the filling. Spread the cheese mixture over the noodles. Top with the remaining noodles and spread the remaining apple pie filling over the top of those.
In a small bowl stir together the flour, brown sugar, oats, cinnamon and nutmeg. Mix in margarine until the mixture is crumbly. Sprinkle over the top of the pie filling.
Bake for 45 minutes in the preheated oven.
Cool for 15 minutes. While the lasagne cools stir together the sour cream and brown sugar.
To serve cut into squares and top with sour cream as a garnish.