Why Did I Do This?

So here's a little story from the retail trenches. My coworker Lily and I were having our usual lunch break chat when she mentioned how much she loves that new coffee drink from across the street, she swears it’s the best part of her day. Well, my competitive spirit kicked in. Later that same afternoon, I convinced myself to create a similar concoction with our own ingredients to surprise Lily and show her we have better taste here! I mean, come on, how hard could it be? It ended up being a bit...off. Instead of getting praise for my effort, Lily was nice but firm about it not tasting great. Now the manager is asking why all these weird flavors are showing up in our store’s coffee menu. Any advice on salvaging this disaster without losing my job and reputation as a good employee? Is my idea of a little friendly competition just too much?