Dulce de Leche: you can find more ways of making Dulce de Leche here. Or you can use store-bought. You will need about 1 1/3 cups of dulce de leche for the whole recipe. If the dulce de leche becomes lumpy (which happens in the oven method, you can place it in a food processor once it comes to room temperature and process until smooth).
Oil: you can use canola oil, vegetable oil, or even avocado or grapeseed oil.
Apples: I used Macintosh apples, use your favorite apple, as they will all work with this lovely recipe.
Glaze: the amount of powdered sugar and milk you will need for the glaze will depend on how thick or thin the dulce de leche is. If using store-bought dulce de leche, several brands can be very different in consistency and texture. Adjust by adding more powdered sugar if the glaze is too thin, and adding more milk if the glaze is too thick.
Sour cream: if you are out of sour cream, feel free to use milk or heavy cream instead.