Giving your Coffee Liquor some *KICK*?
I like drinking the fancy pants, flavored liquors by days end to relax (just a shotglass or 2...)- coffee, creme de cocoa, watermelon shnapps, and just recently picked up butterscotch. ...but they never seem to make them "strong enough". 15% is all you get, it seems (unless you move up to Goldschlager, but I've had enough of that stuff). So is there a tastless or complementary sort of alcohol I could add to the above examples that would spike up the alc content w/o changing the flavor?