I have a recipe for apple pie I want to use. The recipe asks for a cast iron skillet.
Can I use a regular skillet in the oven instead of the cast iron skillet?
Technically, yes, though the crust will likely be less brown and evenly brown than if you use a cast iron skillet, especially if the sides of your regular skillet are thinner than the base. If that is the case, the sides will be less brown than the base of the pie.
You might also have to adjust the cooking time on the recipe as well, so if you're a stickler with following a recipe to the "T", then I'd ask someone to borrow their cast iron skillet :)
I love baking pie in cast iron; it absorbs some moisture that keeps crust crisp. Your skillet may be 'slicker' and let the crust steam a bit more. If it is an enameled, it is much more like baking in glass (which enamel technically is).
The other consideration is heating up time for bottom of the pan. Cast iron allows the top to brown before the bottom gets done. If it is a very juicy recipe, it may bubble up earlier than expected in a thinner skillet.