The recipe for butter coffee, or bulletproof coffee, is attributed to Dave Asprey who had yak butter tea on a trip and was inspired. For the Dave Asprey bulletproof coffee recipe, you should include both butter and brain octane oil (his branded version of MCT oil) and no sugar. Dave is the creator of the bulletproof diet which aim to assist with weight loss and brain function while boosting cognitive function with a diet with high fat content and low in net carbs. He also places an emphasis on high-quality ingredients.