Base and topping:
1 c. quick-cooking oats, ground
1 c. flour
1/2 c. sugar
1 1/2 sticks butter, room temperature
1 tsp cinnamon
1/2 tsp salt
Filling:
1 large apple, cubed
1 tbl sugar
1 tbl flour
1 tsp cinnamon
1 1/2 c. Greek yogurt
1/4 cup sugar
1 egg
1/4 c. flour
Caramel sauce:
Dulce de leche
Some milk
Preheat oven to 350F.
1) Make the base & crumbs: mix together oats, flour, cinnamon, sugar and salt. Add butter. Mix using your fingertips until crumbs form. Press 2/3 of the mixture into a 8x8inch baking dish. Reserve 1/3 for the topping. Bake for approximately 10 minutes or until lightly browned.
2) Make the filling: First, mix apple cubes with 1 tablespoon sugar, 1 tablespoon flour and 1 teaspoon cinnamon and set aside. In another bowl, mix together Greek yogurt, sugar, egg and flour. Pour the mixture over the crust. Sprinkle apples on top (do not press!) and sprinkle crumb topping (don't press as well. It will stick together while baking).
3) Bake at 350F for 25-35 minutes or until set. (closer to 35 mins) Allow to cool, or refrigerate.
4) Make the caramel sauce: Heat up a few tablespoons of the dulce de leche in a small saucepan, add a bit of milk if it's too thick. Make the caramel sauce immediately before serving.