Preheat the oven to 350° F. Grease an 8"x8" metal baking pan and set it aside.
In a medium-sized bowl, mix the dry ingredients. Sift the flour and the cocoa powder to remove any lumps, then add the salt, followed by the baking powder. Set aside.
In a separate medium-sized bowl, cream together the cannabis butter and then white and brown sugar with a hand mixer.
Add the eggs and vanilla to the creamed sugar and beat on medium speed for one minute (the mixture's color should lighten a bit).
Add the dry ingredients to the wet ingredients and beat on low until everything is well incorporated.
Transfer the batter to the reserved greased baking pan. Lightly tap the pan to even out the batter.
If you are adding and any optional toppings, like sea salt, add them now.
Place the pan in the oven to bake for 25-30 minutes. The time will depend on your oven and your brownie consistency preferences. Test the finished brownies with a toothpick* (see notes below).
Allow brownies to cool for 30 minutes before cutting into squares.
Tip: The cannabis butter’s potency depends on many factors, from how long and hot it was cooked to the strength of your starting material. Even the type of cannabis used (for example indica v. sativa) is a factor. To test the potency of your cannabis butter, spread ¼ or ½ teaspoon on a snack and see how that dose affects you after an hour. Then decrease or increase dose as desired. That will provide you with a baseline standard for your recipes.