In a medium bowl, combine gluten-free flour, pecans, oats, sugar (or sugar substitute), cinnamon and salt. Add melted butter and stir until mixture is moistened and crumbly. Set aside.
In a large bowl, toss apples with cinnamon and sugar or sugar substitute. Set aside.
Heat apple cider in a 12-inch skillet over medium-high heat until reduced to ½ cup, about 5 - 7 minutes. Transfer apple cider to a measuring cup or small bowl and add 2 teaspoons lemon juice.
Heat butter in the same (empty) skillet over medium heat. Add apple mixture. It will seem like the pan is too full, but once the apples cook, they will reduce in size. Cook, turning the apples frequently until they begin to soften, about 12 - 14 minutes. Don't fully cook.
Add ½ cup fresh cranberries to the pan. Remove the pan from the heat and stir in the apple cider-lemon mixture until apples are fully coated.
Sprinkle the topping mixture over the apples and cranberries, covering completely. If making ahead of time, cover and refrigerate until ready to bake.
Place skillet on a baking sheet to prevent spills in the oven. Bake at 450°F for 15 to 20 minutes until apples are tender and topping is golden brown. Cool on wire rack for 15 minutes before serving. Delicious with a scoop of ice cream, whipped cream or whipped coconut milk!
This Skillet Cranberry Apple Crisp is delicious served warm or at room temperature. Enjoy!