Preheat the oven to 375.

Chop the chocolate and walnuts if you have not already done so. Have ready a

#20 ice cream scoop and at least two cookie sheets. Put parchment paper on each cookie sheet. This is important.

Sift together the flour, salt, and baking soda. Set aside.

Put the melted butter into a standing mixer bowl, and add the brown and white sugars. Beat the mixture together on medium speed until the mixture has creamed together. Add the vanilla and rum flavoring. Scrape the bowl and beat again. Scrape the bowl and add the eggs. Beat again, then turn the beater down to its lowest setting and slowly add the flour mixture. Mix until all the flour is incorporated, then stir the chocolate and walnuts in by hand.

Take the ice cream scoop and put six scoops of dough on each sheet. Put two of the sheets into the oven, and bake until the cookies are browned about 12 minutes. Cool and the sheet for a few minutes, then remove to cooling racks. Repeat with the remaining cookies.