Heat oven to 350 and line an 8x8 baking pan with greased parchment paper. (I like to rub my parchment paper with the vegan butter, but a vegan spray works well too.)
In a large bowl, whisk together the hot melted butter and sugar.
Add the milk and vanilla to the bowl and whisk to combine.
In a separate bowl, mix together the flour, cocoa powder, baking powder, and salt.
Add the dry ingredients into the big bowl of wet ingredients and mix until combined.
Gently fold in the chocolate chips.
Press the batter into the prepared baking pan, then bake for 30 minutes. The batter will still appear quite gooey, but pull it out of the oven and let it sit on your counter in the pan for 30 minutes.
After 30 minutes, the brownies will be ready to eat, but they will still be warm and soft. You can serve them in a bowl with some vanilla ice cream and eat them while warm (YUM!) or you can take them out of the pan, leaving them on the parchment paper, and wait until they are completely cooled, at which time they will harden and hold their shape.