In a large bowl - combine: flour, sugar, salt, cocoa powder, baking powder, and baking soda.
In a new bowl: gently whisk egg, milk and vanilla until combined
In a new bowl: combine chocolate syrup and melted butter. Stir until smooth.
Combine milk and chocolate mixtures with dry ingredients in large bowl. Mix until smooth.
Gently fold in chocolate chips.
Spray standard muffin pan with baking spray and/or use paper liners.
Place an equal amount of batter into each muffin cup by using a cookie scoop. Measure out 1 to 2 scoops depending on the size of the cookie scoop. Fill the muffin tin no more than ⅔d's of the way full.
Bake 18 - 22 minutes. Muffins are ready when a toothpick or cake tester stuck into the middle is clean when pulled out.
Let the muffins cool for 5 to 10 minutes in the pan then remove from the pan and let them finish cooling on a wire rack.
Notes
Optional Icing Drizzle
Mix : 1 ¼ cups confectioners' sugar with 3 tablespoons milk and ½ teaspoon vanilla extract