Cranberry Apple Slab Pie

Ingredients

• 2 recipes easy pie dough shaped in a rectangular block and chilled for at least two hours, ideally overnight
• 4 ounces (about 3/4 cup) rolled oats
• 1 ounce (about 3 tablespoons) all purpose flour
• 4 ounces (about 7 tablespoons) light brown sugar
• big pinch of salt
• 3 ounces (6 tablespoons) butter, cold and cut into 1/4 inch pieces
• 10 to 12 medium fresh apples (such as golden delicious or granny smith), peeled and cored
• 6 ounces fresh cranberries
• 8 ounces granulated sugar
• 1 teaspoon cinnamon