To prepare filling combine first 4 ingredients (peaches - almond extract) in a large bowl, crushing peaches to help release juices. In a small cup or bowl combine 3 tablespoons of the juice with cornstarch. Stir cornstarch mixture into peaches. Pour mixture into prepared dish.
To prepare topping, combine first 7 ingredients (oatmeal - ginger) in a large bowl. Cut in butter with two knives or pastry blender. Stir in vanilla and almonds (if using).
Sprinkle topping over peaches, pressing down slightly.
Bake for 45-50 minutes or until topping is brown and peaches bubbly.