Fill 2 highball (tall) glasses with crushed or cubed ice.
Add 1 ounce each Kahlúa and 1 ounce tequila to each glass.
Top off each glass with cola and garnish with lime, orange peel, or a maraschino cherry. Serve immediately.
Notes
Tips for Storing
This cocktail is best made fresh. It doesn't store well once the cola is added since the carbonation goes flat quickly. Mix individual drinks to order.
Pre-batch the base: You can mix equal parts Kahlua and tequila in a jar or bottle ahead of time and refrigerate it. When you're ready to serve, just pour over ice and top with cola.
Keep your Kahlua refrigerated after opening. It doesn't require refrigeration, but keeping it cold means it's always ready to go and helps preserve flavor over time.
Use a sealed container for the Kahlua-tequila base. If you've pre-batched it, it will keep in the fridge for up to 2 weeks with no issues.
Leftover cola? Transfer it to a sealed bottle and refrigerate immediately to preserve carbonation. Use within 24-48 hours for best results.