Preheat oven to 350 degrees F (175 degrees C). Spray an 8-inch baking dish with cooking spray.
Whisk flour, salt, baking powder, and baking soda together in a bowl. Beat sugar, oil, egg, lemon juice, and lemon zest together in another bowl. Add flour mixture to oil mixture and stir gently until batter is combined. Pour batter into prepared baking dish. Sprinkle cashews over the top.
Bake in the preheated oven until golden and set, 20 to 25 minutes. Cut into squares and garnish with strawberries.