Mix butter, maple syrup, and powdered sugar with a hand mixer. Add vanilla and beat until creamy. Stir in walnuts. Chill for 30 minutes.
Once chilled, scoop 1 tablespoon sized balls of dough and place on a wax paper lined cookie sheet. Chill again until just ready to dip (at least 10 minutes).
Melt your candy in a microwave safe bowl according to package directions. Dip each truffle in the bowl of chocolate.
Do not roll it around, use a spoon to spoon chocolate over the top. Lift onto a fork carefully and tap to remove excess chocolate. Place on a wax-paper lined cookie sheet. I find it best to use a toothpick to help the truffle slide off the fork without disturbing too much of the coating.
Note: these truffles soften quickly. If you find them getting to soft, re-chill them and only remove a few at a time to dip.
Chill dipped truffles for just a few minutes, until coating is semi-hard. Meanwhile transfer the remaining chocolate to a squeeze bottle (or a plastic bag with the tip cut off) and pipe swirls or swipes of chocolate over the top for decoration
To keep chocolate warm, you can heat an electric griddle to 200F and cover it with two kitchen towels. Then place the bowl of melted chocolate on top to keep it warm and liquid while you dip.