Preheat the oven to 350 degrees.
Whisk the dry ingredients together in a large mixing bowl.
In a separate bowl, beat together the milk, egg, melted butter, and vanilla.
Stir the wet ingredients into the dry ingredients, being careful not to over mix.
Fold the chopped cranberries into the batter. Divide the batter evenly amongst 12 muffin tins, filling almost to the top.
In a separate bowl, use a fork or your fingers to crumble together the butter, flour, sugar, and ginger for the crumb topping. Spread over the tops of the muffins.
Bake in the oven for 18-20 minutes, until an inserted toothpick comes out clean.
Cool for 10 minutes in the tins and then move to a cooling rack.