Remove stem from apples and insert Popsicle sticks. Place on wax paper or silpat. Set aside.
In a saucepan large enough to hold all ingredients (excluding apples) melt butter. Add sweetened condensed milk, corn syrup, brown sugar and salt. Stir to a boil, preferably using a heat resistant rubber spatula.
On medium heat continue to stir until caramel reaches 245°F. Do not cook too high as it will make bottom of pan scorch.
Remove from heat and pour in vanilla extract.
Carefully tilt pan to obtain a deep caramel layer. Dip one apple at a time rotating in caramel until well coated. Place on wax paper or silpat.
Melt chocolate coating according to manufactures directions. Let cool until slightly thickened. Daub a small amount of chocolate coating on each M&M® and wait a few second to allow coating to become slightly firmer and make attaching easier.
