Make the brownies. Preheat the oven to 340 degrees Fahrhenheit. Line or grease a 9×9 inch baking pan with parchment paper or coconut oil. In a large bowl, mix together the sugar and coconut oil. Add the rest of the wet ingredients and mix until smooth. Add the dry ingredients and mix until well combined. It will be a thick, wet consistency. Scoop or pour into your pan. Bake for 45 minutes, or until you can stick a fork in the middle and it comes out clean. Place the pan on a cooling rack to let the brownies set. You can also let them cool and set overnight and frost the next day, covered with a tea towel.
Make the frosting. Blend all the ingredients until very smooth. You may need to add more non dairy milk to get the right consistency. Spread on your cooled brownies (you will have extra frosting, I assume this isn’t a problem).
Drizzle the frosted brownies with tahini, and add salt and sesame seeds if using. Cut into whatever shape and size you like. Enjoy!