1. Preheat oven to 375 degrees F. Mix 1 cup sugar, cornstarch and salt in a large bowl. Add egg and almond extract; mix well. Add peach slices to bowl; toss gently to coat with sugar mixture. Arrange peach slices in pie crust.
2. For topping, combine 1/4 cup sugar, brown sugar and flour in a small bowl. Cut in margarine, using pastry blender or 2 knives, until crumbly. Sprinkle topping over peaches.
3. Bake until golden brown, about 30 minutes. Serve warm or cold.