In the bowl of a stand mixer, beat together butter and sugar until light and fluffy. Gradually add flour, Pillsbury Funfetti Holiday Cake Mix, vanilla and salt and mix thoroughly.

One tablespoon at a time, add milk until mixture forms a dough-like consistency.

Roll dough into 1-inch balls and place on a baking sheet lined with parchment paper.

Chill for 30 minutes.

Meanwhile, melt chocolate in a microwave safe dish at 30-second intervals, stirring frequently.

Using a toothpick or a fork, dip each truffle into the melted chocolate. Shake off excess by tapping fork against the side of the dish.

Place truffles on baking sheet lined with parchment paper and sprinkle with M&M's Holiday Minis. Repeat until all truffles are coated.

Allow chocolate coating to harden then store in the refrigerator until serving.