To make the apples: melt the red and green candy melts and place them in a squeeze bottle (can be found at stores like Michaels). I find that working with a squeeze bottle is cleaner and easier. Squeeze some red into the apple mold for the apple, green for the stem. Tap it on the counter a few times to settle the candy and then freeze until hardened (about 3-5 minutes). They should easily release.
To make the chocolate dipped Oreos: melt your chocolate in a large microwave safe bowl. You can dip the Oreos directly in the chocolate or you can use a mold. If you are using a mold, squeeze (from a bottle) or spoon some chocolate onto the base of the mold. Tap to level. Add the Oreo and cover with more chocolate. Tap to cover and freeze until hardened (about 5 minutes).
Attach the apples to the Oreos with a dab of melted chocolate.