Preheat the oven to 325°F. Lightly spray muffin tin wells baking dish with cooking spray.
In a bowl, combine the sugar, flour, cocoa powder, and salt.
In a bowl, whisk together the egg, oil, and vanilla. Then fold in the melted chocolate chips.
Combine the dry ingredients with the wet ingredients.
Pour the batter into the prepared wells and use a spatula to smooth the top. Bake for about 10 minutes or until mostly firm but slightly underdone in the middle.