Instructions

1. Preheat your oven to 350°F (175°C) and generously grease a baking dish with butter or a non-stick spray.
2. In a large mixing bowl, combine the all-purpose flour and granulated sugar.
3. Add the cold, cubed unsalted butter to the flour and sugar mixture. Using your fingers or a pastry cutter, cut the butter into the mixture until it resembles coarse crumbs. This is your streusel base.
4. Stir in the beaten egg and vanilla extract into the streusel base. Mix until a dough forms.
5. Press two-thirds of the dough into the bottom of the greased baking dish, forming a thick, even crust.
6. Spread your chosen fruit filling evenly over the streusel crust. This adds a juicy, sweet layer to the dessert.
7. Take the remaining dough and crumble it over the fruit filling, creating the characteristic streusel topping.
8. Bake in the preheated oven for about 40 minutes, or until the streusel topping is a golden brown and the fruit filling is bubbling and aromatic.
9. Once baked, remove the dish from the oven and allow it to cool slightly before cutting into it. This dessert is best served warm, but is equally delightful at room temperature.