Add the strawberries, lemon juice, sugars, and all-purpose flour to a large bowl. Toss until the strawberries are well coated. Pour the strawberries into a 9-inch pie dish. Set aside.
In a medium-sized bowl, combine all ingredients for the topping. Mix until crumbly and everything is incorporated. Sprinkle it over the strawberries in an even layer.
Bake for 45 minutes. Allow the crisp to cool slightly.
Notes
Note: It's optional, but totally recommended, to eat this while still warm, topped with vanilla ice cream.