You can supercharge your bulletproof coffee by adding several things. High quality cacao is the most popular choice since it not only adds a great taste, but it adds many health properties to the standard recipe. Cacao opens up blood vessels allowing more fats to enter the brain. Another popular additive to the standard bulletproof recipe is Ginkgo Biloba. Ginkgo Biloba like Cacao, increases blood flow to the brain which helps push more healthy fats in.
There are thousands of people around the world who are experimenting with different combinations of ingredients to absolutely super charge the standard recipe. You can find many discussions around the internet, if you do a quick search, you can easily find these discussions. People have tried adding avocado oils, fish oils, turmeric, cinnamon, cloves, and a variety of other potent super foods (and all with good effects).
The most important thing you should keep in mind though when modding the bulletproof coffee is that everyone is different and what works for one person may not work for you. Because of this, you'll need to experiment and play around with different items to see if they work for you or not.