Decarb a quarter of an ounce cannabis in the oven at 240 degrees for 30 to 40 minutes to activate the THC. Grind cannabis, but not too fine.
Pour cannabis into a heatproof jar. Add condensed milk. Close lid. Place sealed jar inside a slow cooker. Pour hot water around the edges until three-fourths of the way up the jar. Cook on high for 4 hours.
Using a fine sieve, strain cannabis condensed milk into a glass jar. Use immediately, or refrigerate until needed.
In a pot over low heat, melt the butter, coconut milk, and condensed milk, stirring continuously until you can see the bottom of the pot for 2-3 seconds when dragging the spatula through.
Pour onto a greased plate, then chill for 1 hour.
Scoop out roughly one teaspoon of chilled mixture and roll into 1-inch sized balls.