Preheat your oven to 350°F (175°C). In a large mixing bowl, combine gluten-free flour, rolled oats, brown sugar, baking soda, and salt. Stir until well mixed. Pour in melted butter and mix until it resembles coarse crumbs. Reserve 1 cup of this mixture for topping.
If making homemade caramel, melt caramel candies with a splash of cream over low heat until smooth. Set aside to cool slightly.
Press the remaining oat mixture into the bottom of a greased or lined baking dish. Sprinkle chocolate chips over the crust, drizzle caramel sauce over the chocolate chips, and crumble the reserved oat mixture on top.
Bake for 15-20 minutes until the top is golden brown. Let cool completely in the pan before cutting into squares.