Place chocolate in a dry bowl. In a heavy-bottomed small saucepan, bring cream and corn syrup to a boil, then immediately pour over chocolate. Allow to sit two to three minutes. With a rubber spatula, stir the chocolate mixture, starting from the center of the bowl and working your way outward. Once mixed, gently stir in butter.
Let cool at room temperature, stirring occasionally, about 30 minutes. Once ganache is stiff enough to hold its shape, use a two-teaspoon ice-cream scoop to portion it onto a parchment-lined sheet pan. Refrigerate until firm, about 30 minutes.
Roll each scoop between palms to create a ball, then roll in coating. Return to refrigerator until firm.
