Put the butter and Kahlua into the food processor and blend well, until the butter starts to whip and the liquid is no longer pearling but rather completely emulsified together. Then just scrape it into a sauce container and enjoy!
Notes
Making it Vegan: just use a vegan-friendly butter of your choosing, or even a refined coconut oil so that you can be sure it won't interfere with the coffee flavor. Use a vegan coffee liqueur, or espressso with coconut condensed milk, if you can't find one. Customizing the Sweetness Level: for a more or less sweet option, add in some coffee or condensed milk within that 2.5 tablespoons of liquid per half stick of butter. How Long to Store: this coffee butter sauce is made with refrigerator-stable ingredients, so it will stay good in the fridge for up to a month in a well-sealed container.Non-Alcoholic Version: in place of the kahlua add 1oz. of strong espresso, cold or room temperature, plus ½ to 1 tablespoon sweetened condensed milk.