Preheat oven to 375 degrees. Line a baking sheet with parchment paper; set aside. In a medium bowl, sift together flour, baking soda, ginger, cinnamon, cloves, and salt; set aside.
In the bowl of an electric mixer fitted with the paddle attachment, cream the butter and brown sugar on medium speed until light and fluffy, about 2 minutes. Add egg; beat until combined, scraping down sides of bowl once. Add molasses; beat until combined, and scrape down sides of bowl. Add the flour mixture and raisins; beat on low until dough just comes together, about 1 minute. Cover with plastic wrap; place in refrigerator to chill 30 minutes.
Remove dough from refrigerator, and turn out onto a clean work surface. Divide into 2 equal pieces, and shape each piece into a 12-inch log about 1 1/2 inches in diameter. Place on prepared baking sheet, at least 3 inches apart.
Place in oven, and bake until logs are golden but still very soft to the touch, 20 to 22 minutes. The logs will flatten out and lengthen as they bake and get slightly puffy in the center. Transfer baking sheet to a wire rack to cool completely. Slice logs into 1-inch-wide bars. Hermit bars can be stored in an airtight container at room temperature up to 1 week.