Preheat the oven to 350°F (175°C).

In a large bowl, combine all of the apple filling ingredients and toss to evenly coat the apples.

Transfer the apples to an 11-inch cast iron skillet (or a deep pie dish or baking pan).

Bake the apples for 10 minutes to soften them slightly.

While the apples bake, prepare the crisp topping. In a large bowl, whisk together the oats, almond flour, brown sugar, salt, and cinnamon.

Add the cold cubed butter and use your fingers to work it into the dry ingredients until the mixture holds together when squeezed.

Remove the apples from the oven and evenly distribute the crisp topping over them.

Return the dish to the oven and bake for 35-40 minutes, or until the topping is golden brown and the filling is bubbling around the edges. If the top browns too quickly, cover loosely with foil and continue baking.

Let the apple crisp cool for about 15 minutes before serving.