135 g / 1 cup Diced Dried Plums
50 g / 1/3 cup dried sour cherries, coarsely chopped
200 g / 1 1/2 cups all-purpose flour
45 g / 1/3 cup whole-wheat pastry flour or Kamut flour
25 g / 1/4 cup Dutch-process cocoa powder
5 g / 1 teaspoon baking powder
5 g / 1 teaspoon baking soda
2 g / 1/2 teaspoon salt
240 g / 1 cup buttermilk
80 g / 1/2 cup brown sugar
2 large eggs
75 g / 1/3 cup unsalted butter, melted
75 g / 1/4 cup Dried Plum Purée
5 g / 1 teaspoon vanilla extract
80 g / 1/2 cup bittersweet chocolate, coarsely chopped
Coarse sugar, such as turbinado
Preheat the oven to 400F [200C]. Oil 12 muffin cups or line with paper liners.
Soak the dried plums and sour cherries in warm water for 5 minutes. Drain.
In a bowl, whisk together the flours, cocoa powder, baking powder, baking soda, and salt.
In another bowl, whisk together the buttermilk, brown sugar, eggs, butter, purée, and vanilla. Mix the buttermilk mixture into the flour mixture until just combined. Fold in the dried fruit and chocolate chunks.
Fill the prepared muffin cups just below the rim. (Each muffin will have about 85 g batter.) Sprinkle coarse sugar on top.
Bake until a skewer inserted into the center comes out clean, about 18 minutes. Cool for 5 minutes, then remove from the muffin cups and cool completely.