Preheat the oven to 350ºF. Line 10 slots of a muffin pan with paper liners. Set aside.
Toss the frozen cranberries in 1 tablespoon of flour. 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 cranberries into the batter, divide among the paper-lined muffin pans and bake for about 23–25 minutes. Use a cake tester to check that the muffins are properly baked. Let cool.