Melt the butter with the chocolate in the top of a double boiler placed over medium heat, stirring frequently to keep the chocolate from scorching.
In a large mixing bowl whisk the sugar, flour, and kosher salt together.
Add the eggs and stir until the batter is smooth and well blended, about 30 seconds.
Pour in the melted butter and chocolate, stirring until smooth.
Add the chopped pecans and the vanilla extract.
Line 16 to 18 regular size muffin cups with parchment or paper liners. You can also use Silpat’s silicone muffin molds. Using a large ice cream scoop or spoon, fill each cup about ⅔ full.
Bake at 325-degrees for 30 minutes. Check the cakes after 25 minutes, a toothpick should come out clean when they’re done; a few crumbs are okay. They should still be soft and fudgy in the center. Take care not to over bake.
Cool slightly in the pan then finish cooling on a wire rack.