Prep. Preheat the oven to 375˚F. Lightly grease an oval baking dish or an 8-inch brownie dish with cooking spray. Layer the strawberries on the bottom of the dish and toss with lemon juice.
Make the sugar mixture. In a small mixing bowl, combine the flour and 1 tablespoon light brown sugar; mix until incorporated. Add the brown sugar mixture to the strawberries and mix to combine. Set aside.
Make the crumble topping. In a mixing bowl, whisk together almond flour, oats, baking powder, cinnamon, salt, and remaining brown sugar. With your fingers, rub in butter until the mixture is crumbly. Press the mixture between your fingers into small lumps and sprinkle over strawberries.
Bake. Put the baking dish in the oven and bake for 30 to 35 minutes until the top is golden brown and the fruit is bubbling.
Finish and serve. Remove from the oven and let it rest for about 8 to 10 minutes before serving. Optionally, top with a scoop of vanilla ice cream.