Preheat your oven to 350°F. Grease an 8x8-inch baking pan.
In a small saucepan, melt together the chocolate chips and butter, making sure to remove the sauce pan from the heat just as it’s finished melting to ensure you don’t burn the chocolate.
Pour the melted chocolate into a mixing bowl. Add the sugar, non-dairy milk, and vanilla and mix well. Now add the flour, cocoa, baking powder, and salt and mix until combined. Finally, add the walnuts(if using).
Pour the batter into the prepared baking pan and bake for 30–35minutes, until the brownies are pulling away from the sides of the pan and a toothpick inserted in the center comes out with just a few moist crumbs on it. Let the brownies cool and set overnight.This is the key to perfect gooey brownies.
To store, let the brownies cool completely, then cover with foil or plastic wrap and keep at room temperature for the best texture. For longer storage put in an airtight container and store in the fridge.