Plum Poppy Seed Muffins
- 6 tablespoons (3 ounces or 85 grams) unsalted butter, melted and browned
- and cooled, plus butter for muffin cups
- 1 large egg, lightly beaten
- 1/4 cup (50 grams) granulated sugar
- 1/4 cup (50 grams) packed dark or light brown sugar
- 3/4 cup (180 grams) sour cream or a rich, full- fat plain yogurt
- 1/2 cup (60 grams) whole-wheat flour
- 1 cup (125 grams) all-purpose flour
- 3/4 teaspoon baking powder
- 3/4 teaspoon baking soda
- 1/4 teaspoon table salt
- Pinch of ground cinnamon
- Pinch of freshly grated nutmeg
- 2 tablespoons (20 grams) poppy seeds
- 2 cups pitted and diced plums, from about 3/4 pound (340 grams) Italian prune plums (though any plum variety will do)
Preheat your oven to 375 degrees. Butter twelve muffin cups.
Whisk the egg with both sugars in the bottom of a large bowl. Stir in the melted butter, then the sour cream. In a separate bowl, mix together the flours, baking powder, baking soda, salt, cinnamon, nutmeg, and poppy seeds, and then stir them into the sour- cream mixture until it is just combined and still a bit lumpy. Fold in the plums.
Divide batter among prepared muffin cups. Bake for 15 to 18 minutes, until the tops are golden and a tester inserted into the center of a muffin comes out clean. Rest muffins in the pan on a cooling rack for 2 minutes, then remove them from the tin to cool them completely.
Do ahead: Generally, I think muffins are best on the first day, but these surprise me by being twice as moist, with even more developed flavors, on day two. They're just a little less crisp on top after being in an airtight container overnight.