Preheat oven to 375°F. Grease an 9-inch square baking dish or 8-inch x 11-inch baking dish.
Place the peaches into the greased baking dish; add the sugar, cornstarch, lemon juice and cinnamon on top, stir and set aside.
In a small bowl, combine the oats, flour, brown sugar and salt. Cut in butter using a fork or your hands until mixture resembles coarse crumbs. Sprinkle the streusel mixture over the peach mixture.
Bake until the crisp topping is golden brown and the filling is bubbly, about 35-40 minutes. Allow to cool for a few minutes. Serve warm with a scoop of ice cream, if desired.
Video
Notes
Storage: Store any leftovers in an airtight container. They will last about 3-4 days in the fridge.Freezer Instructions: After baking the apple crisp, allow it to cool completely, then cover it with two layers of aluminum foil. You can freeze it for up to 3 months. When ready to bake, thaw it overnight in the fridge and warm it at 375°F oven for 15-20 minutes or until heated through.