In a small saucepan, heat ? cup plus 2 tablespoons heavy whipping cream over medium heat, stirring constantly, until it just begins to simmer.
Stir in 1 tablespoon butter until melted.
Add 8 ounces white chocolate baking bars and stir continuously over low heat until the chocolate is completely melted and smooth. Remove the saucepan from the heat and pour the mixture into a small glass bowl.
Let the mixture cool completely, then refrigerate for about 2 hours, or until firm enough to scoop.
Scoop and roll the chilled mixture into approximately 1-inch balls. Place the truffles on a wax paper-lined baking sheet. Freeze the truffles for 30 minutes.
Place the remaining 8 ounces white chocolate baking bars in a microwave-safe bowl. Microwave in 30-second intervals, stirring after each interval, until the chocolate is completely melted and smooth.
Dip truffles into melted chocolate and place onto wax paper. Sprinkle with white jimmies. Let set in the refrigerator to harden.
Notes
These look really fancy but they are actually so simple to make!