Add white chocolate chips to a medium mixing bowl. Set aside.
In a small saucepan melt the butter and add lemon zest. Stir in heavy cream and let it come up In temperature until just before it is boiling.
Pour the cream mixture through a fine-mesh sieve over the white chocolate chips. Add the lemon and vanilla extract. Add the food coloring, then stir until the mixture is smooth.
Cover and refrigerate the chocolate chip mixture until it is firm enough to handle, about 30 minutes.
Scoop 1 - 1 ½ tablespoons of the chocolate chip mixture and form into balls, then roll the balls in the powdered sugar.
Refrigerate the truffles for at least 1 hour before enjoying.
When you are heating the cream and butter together, be sure to only let it simmer for a couple of seconds, not longer. You definitely don't want to let it boil. If this happens the ingredients will begin to separate and you will have to throw it out and start over.
The hot mixture poured over the top of the chocolate chips will melt them. It’s important to work quickly on these steps so that you can get everything mixed while the ingredients are still warm and melted.
The balls should be about 1 inch in diameter. It usually works to use 1-1 ½ tablespoon size scoop to measure out the correct amount of batter.