Coffee and liquor is a winning combination. Derived from the Spanish word "coraje" (courage), the Carajillo is popular in Spain and Spanish speaking countries such as Mexico and Colombia. One origin story of the Carajillo involves Spanish soldiers who mixed rum into their coffee while stationed in Cuba. The Carajillo has a lot of variations. Here's my simple one:
Combine in a shaker with ice, shake with the energy that comes from courage, and strain into a chilled glass.
Licor 43, a Spanish liqueur that's a key part of the 43 Up and my Daiquiri 43, is the star of the Carajillo. Many, if not most, versions of the Carajillo use Licor 43. To me that's the way it should be because Licor 43 is a Spanish spirit. After all, you wouldn't use something other than Irish whiskey in an Irish Coffee, would you? As for the type of coffee, that's up to you. You can use espresso (that's common) or regular coffee instead of cold brew. Similarly, you can serve the Carajillo hot or cold, or on the rocks, or you can use different proportions of the coffee and Licor 43 ... you get the idea. It's all about striking a balance between the strength and sweetness of the cocktail's two components.
So do you want some dark liquid courage? There's only one answer: si!