Grease a
13 x 4 inch pullman loaf pan with butter and dust with rye flour, including the lid. Set aside. Combine the soaker, flour mixture, salt and molasses in the bowl of a stand mixer. Fit mixer with paddle attachment and mix on low speed for 2-3 minutes until everything is thoroughly combined, scraping down the sides of the bowl from time to time. Increase speed to medium and mix for an additional 2-3 minutes, stopping to occasionally scrape down the sides of the bowl. Mixture will be quite sticky.