Then, prepare your two cakes mixes. In a large bowl pour in your spice cake mix. In another large bowl, pour in your caramel apple cake mix. To each cake mix, add 2 eggs and 1/3 cup vegetable oil. Mix until just blended. Cover both and refrigerate for about 30 minutes.
Add 1 cup of powdered sugar to a bowl; set aside.
Remove the bowls of batter from the refrigerator. Take about 2 teaspoons of spice batter and roll into a ball. (If the dough is sticky, just add a bit of powdered sugar to your hands to prevent it from sticking.) Repeat with the caramel apple batter. Then, gently roll the spice and apple dough balls together to make one large ball.
Carefully roll the dough ball into the prepared bowl of powdered sugar to coat. Place the dough balls on a baking sheet about 2 inches apart. Repeat with the remaining dough.
Bake for about 10 minutes or just until the cookies are slightly golden. Transfer to a wire rack to cool.
In the meantime, prepare your glaze. Whisk together the powdered sugar, milk, and caramel sauce. Add more milk to thin the glaze or more powdered sugar to thicken. You want a drizzling consistency. Then, put the glaze in a plastic baggie. Snip off a very small portion of one corner and drizzle glaze over your cooled cookies. (A piping bag can also be used or drizzle with a fork.)