Combine the flour, brown sugar, oats, cinnamon, and salt in a bowl. Stir well to combine.
Cut the butter to the oat mixture.
Scatter the oat topping, evenly in chunks, over the top of the apples in the Dutch oven.
Place lid on dutch oven
Place briquettes on and under the Dutch oven
bake until the top is golden and the apple filling is bubbling, about 55 to 60 minutes.
Cool the apple crisp before serving warm