In a medium saucepan, melt butter over medium-low heat.
Turn heat off and whisk in cocoa.
Add about 1/2 cup sugar and 2 Tbsp Peppermint Syrup, beating with electric mixers on medium speed; continue to add sugar and Torani a bit at a time, until all sugar and syrup are mixed in and the frosting is a good consistency for spreading (add more syrup if needed).
Add milk and beat until smooth. Makes about 2 cups; enough for 30 cupcakes or brownies or 2 9-inch cakes.