APPLE CRUMB TORTE (or SHEET CAKE)

This easy-to-make apple cake is a great dessert for potlucks, parties & visitors. I serve it still warm with a big scoop of ice cream or cold from the fridge. Everyone loves this easy apple dessert!
I halved ingredients and still had plenty. Dez says needs more apple & to break down more and the lemon should be in apples not in the biscuit pastry. I thought some chopped pecans on top drizzles with maple syrup  or ACV would be nice and a lot less sugar.

Ingredients (brackets are from sheet cake recipe)
200g (1 ½ cups) unsalted butter, divided
1 (⅓ cup) white sugar
½ teaspoon (few drops) vanilla extract
1 large egg
4 cups sifted SR (all-purpose flour, divided)
750g fresh or canned apples – peel, core & slice (5 apples) – try MORE
1 ⅓ cup applesauce, sweet or unsweetened
1 teaspoon lemon zest, freshly grated
1 tablespoon lemon juice (NI)
1 tsp (½ teaspoon) ground cinnamon
2T brown sugar (½ cup white or brown sugar)

1.  Lightly grease a quarter-size baking sheet (9×13-inch) and preheat your oven to 350°F (180°C).
In the bowl of a stand mixer fitted with the paddle attachment, add 3/4 cup butter, 1/3 cup sugar, vanilla extract, 2 cups all-purpose flour, and egg. Beat until everything is incorporated. Spread the dough onto the baking sheet. Put the baking sheet in the fridge while you make the apple and crumble layer.
Leave the remaining 3/4 cup butter on the kitchen counter to get to room temperature.
Peel and core the apples and chop them into small chunks. Mix the apple chunks with the lemon zest, lemon juice, cinnamon and apple sauce. Set aside.
For the crumb topping: In the bowl of a stand mixer fitted with the paddle attachment mix the remaining soft butter with 2 cups of flour and 1/2 cup sugar (see Note 4). The mixture will be crumbly.
To assemble the cake, spread the apple mixture onto the dough layer. Then use your fingers to crumble the crumbs on top. Press some crumbs together to form bigger crumbs, you don’t want the crumbs to be too fine.
Bake for 45 minutes until the crumbs are lightly golden.
Let the cake cool off completely. It will be a little bit soft while hot.
Serve with whipped cream or vanilla ice cream!

COMMENTS FROM OTHERS: The secret of extra delicious German Streusel is to make them bigger. Use your hands and rub the dough between your fingers, press the smaller crumbs together and sprinkle them over the cake.
(from Family Circle 1969 but similar at https://platedcravings.com/german-apple-streusel-sheet-cake/ & https://www.365daysofbakingandmore.com/easy-apple-crumb-cake/)