In a large saucepan, combine the cranberries, water, and sugar. Bring to a simmer, stirring to dissolve the sugar, and when the sugar is completely dissolved and the cranberries are soft (but haven't burst), take the pan off the heat and let cool to room temperature.
Strain the poached cranberries (you can save the liquid for cocktails or for another batch of poached fruit) and blot them on a paper towel to dry them before tossing them with 10 grams of flour to coat them. Freeze them for 10 minutes to firm them up while you make the gingerbread muffin batter.
To make the muffins
Preheat the oven to 350ºF. Line 10 slots of a muffin pan with paper liners. Set aside.
In a medium bowl, whisk together the 200 grams flour, baking powder, baking soda, salt, and the spices. Set aside.
In the bowl of an electric mixer fitted with the paddle attachment, beat together the butter and sugar until light and fluffy. Add the molasses, then the eggs one at a time, beating and scraping down the mixer bowl as needed. Add the vanilla.
Dump in a half of the dry ingredients, then the buttermilk, and the rest of the dry ingredients.
Fold the flour-coated frozen poached cranberries into the batter, divide among the paper-lined muffin pans and bake for about 23–25 minutes. Let cool.