Infuse butter or coconut oil by simmering water, butter and plant material for several hours. Cannabinoids are soluble in alcohol and fat. This step makes so called "cannabutter". You will have to add water several times to keep the butter about 1" / 2.5cm above pot's bottom. If the water level is too low, plant material may burn out and become useless. After 4 to 6 hours, your solution will become glossy on top. Separate the fat from plant material. Place - still liquid - butter with water in a bowl at room temperature and wait for it to solidify. Don't place the solution into fridge as solidifying too fast may leave impurities in the butter.
Get rid of water from underneath. The butter can now be frozen for several months.
Find a cake recipe which calls for larger amounts of butter. Chocolate brownies are a great choice.
Bake a cake and divide it into equal pieces. For example, if I use butter infused with 30g of plant material, I cut the cake 5x6 to have 30 pieces.