Melt chocolate gently in the microwave.
In a bowl, whisk together flour, baking powder, baking soda, and salt in a medium bowl; set aside.
In a mixer, beat butter and sugar.
On low, add the melted chocolate.
Raise to medium and add eggs.
Add vanilla.
Add sour cream.
On low speed, add half the flour mix, then the water and rest of the flour.
Divide into 12 muffins liners and bake about 20 mins until done.
Let cool on a rack.