Make the pastry dough in a food processor. Combine the flour, chilled butter, sugar and salt. Then slowly add the water until the dought begins to clump. Roll into two balls and flatten into round discs. Place into the refrigerator for 30 minutes to chill.
Peel and core the apples. Slice into quarters.
In two small cast-iron skillets placed on the stove-top at low-medium heat, divide the butter and place into each. Melt the butter. Once the butter has melted, place the sugar into the skillets and mix until combined.
Place the apples into the butter and sugar, core side down - approximately 3 quarters per skillet (you may cut the remaining quarter into smaller sizes to fill the gaps). Cook for about 10 minutes. The butter and sugar will begin to caramelize.
Flip the apples with a fork, carefully to keep them in tact. Cook for about 5 minutes more and then remove from the heat.
Prepare the dough, roll out to slightly overlap the edge of the skillet. Place the dough on each skillet, tuck the sides into the inside of the pans.
Place into a preheated oven (425 degrees) and cook for 20-25 minutes. Remove once the crust is gently golden brown.
Remove from the oven once the crust is gently golden brown. Let cool for about 10 minutes. Then place a plate on the top of the skillet, flip and serve.