How do you make gramma pie?

To make grandma pie, start with a buttery pie crust and fill it with a mixture of fresh fruit, typically blueberries or cherries, combined with sugar and a bit of lemon juice for brightness. Pour the fruit filling into the crust, then top it with a crumbly streusel made from flour, oats, brown sugar, and butter. Bake until the crust is golden and the filling is bubbly, then let it cool before serving. Enjoy with a scoop of vanilla ice cream for a delightful treat!