Step 1: Preheat your oven to 375°F (190°C). Line a 12-cup muffin tin with paper liners or grease generously.
Step 2: To make the crumb topping, combine ½ cup all-purpose flour, ⅓ cup light brown sugar, ½ teaspoon ground cinnamon, ¼ teaspoon ground green cardamom, and a pinch of salt in a small bowl. Pour in the ⅓ cup melted unsalted butter and mix with a fork until moist crumbs form. Set aside.
Step 3: In a large bowl, whisk together 3 cups all-purpose flour, 1 tablespoon baking powder, and ½ teaspoon ground cinnamon. Set aside.
Step 4: In a separate medium bowl, cream together ½ cup softened unsalted butter, 1 cup white sugar, and ⅓ cup light brown sugar until light and fluffy.
Step 5: Beat in the 2 eggs one at a time, then stir in the ¼ teaspoon vanilla extract. Mix well.
Step 6: In a small bowl, whisk together the ½ cup buttermilk and ½ cup sour cream.
Step 7: Gradually add the dry ingredients to the wet ingredients, alternating with the buttermilk mixture, beginning and ending with the dry ingredients. Mix until just combined. Be careful not to overmix.
Step 8: Gently fold in the 1 cup cranberry sauce into the batter. Do not overmix; just enough to distribute the sauce.
Step 9: Divide the batter evenly among the 12 muffin cups, filling each about two-thirds full.
Step 10: Generously sprinkle the prepared crumb topping over the top of each muffin.
Step 11: Bake for 20-25 minutes, or until a toothpick inserted into the center of a muffin comes out with moist crumbs. The tops should be golden brown.
Step 12: Let the muffins cool in the tin for a few minutes before transferring them to a wire rack to cool completely.