To make the pistachio paste: In a food processor, pulse the pistachios until finely ground. , Add the sugar, flour, and salt to the food processor and pulse to combine with the ground pistachios. Add the butter and pulse in 2-second intervals until the butter is pea-sized.   , Add the egg and extract, and process until smooth. Transfer the paste to a small bowl and store, covered, in the refrigerator until ready to use. (The pistachio paste can be made up to 5 days in advance. If stored for more than 2 hours, allow the pistachio paste to sit at room temperature for 10 to 15 minutes before using; this will make it easier to spread.) , To make the dough: In a large bowl or the bowl of a stand mixer, combine all the dough ingredients. Mix using a spoon (if mixing by hand) or the flat beater attachment (if using a stand mixer) until a sticky, batter-like dough forms, about 1 minute on medium speed. If mixing by hand, there may be some lumps — that's OK. It’s normal for the mixture to resemble cake batter at this stage.  , Cover the mixture and set it aside for 20 minutes. It will begin to firm up slightly during this time and look more like dough than batter. Then, on a greased or (gluten-free) floured work surface, gently knead the dough — fold the dough in half towards you (use a bowl scraper for assistance, if needed), then pat it down, rotate the dough 90° (a quarter turn) and fold again — until it becomes firmer to the touch, smoother, and easier to handle, 5 to 6 times. As you work, dust your work surface and the dough lightly with gluten-free flour (or apply more grease) as needed to prevent sticking. The dough may still be sticky to the touch but should have some bounce and body by the end of kneading.  , Return the dough to the mixing bowl, cover, and allow it to rise for 40 minutes, or until slightly puffy.  , To assemble: Lightly grease a tea loaf pan. In a small bowl, stir together the diced cranberries and flour; set aside.   , On a greased or (gluten-free) floured surface, gently deflate the soft dough and pat or roll it into a rough 9" x 14" rectangle with one of the long edges facing you. , Spread the pistachio paste evenly over the entire surface of the rectangle, leaving a 1" bare margin on the long edge farthest away from you. (A small offset spatula is a helpful tool here.) , Sprinkle the diced cranberries over the pistachio paste, followed by the chopped pistachios. , Starting with the long edge near you, roll the dough into a cylinder and pinch the seams to seal. , Use a bench knife or serrated knife to cut the log in half lengthwise to make two pieces of dough, each about 14" long; cut carefully to prevent too much filling from spilling out. With the exposed-filling side up, alternate overlapping the two pieces together to form a twist, then tuck the ends underneath. (It’s OK if some of the now-exposed inner dough coils tears slightly at this point.) Place the log into the prepared pan.    , Cover the loaf and allow it to rise for 45 to 60 minutes, or until it’s puffy and has risen above the edge of the pan by about 1" in the center.   , While the dough is rising, preheat the oven to 350°F.  , Bake the cranberry bread for 30 minutes, then tent with foil and continue baking for 25 to 30 minutes, or until the bread is deep golden brown. The internal temperature should reach between 195°F and 205°F on a digital thermometer when it’s done.  , Remove the bread from the oven and immediately loosen the edges from the pan with a heatproof spatula or table knife. Let the bread cool in the pan for 10 minutes, then turn it out onto a wire rack to cool completely.  , Finish by dusting the loaf with confectioners’ sugar, if desired. Slice and serve at room temperature.  , Storage information: Store any leftover gluten-free cranberry bread, well wrapped, at room temperature for up to 2 days. After 2 days, rewarm individual slices briefly in a toaster, if desired. Freeze for longer storage.