An overnight sponge made with stout creates a rich, complex flavor that matches well with bittersweet chocolate and dried tart cherries. Because yeast feeds on the sugar in the beer, keep the sponge in the refrigerator to control the yeast's growth. A sprinkling of pearl sugar (available at gourmet stores and large supermarkets) adds texture.
1. Lightly spoon flour into dry measuring cups; level with a knife. Combine 2 cups flour, beer, and yeast in a large bowl, stirring with a whisk. Cover and refrigerate 8 hours or overnight.
2. Remove mixture from refrigerator; let stand 1 hour.
3. Add 2 cups flour, 1 tablespoon granulated sugar, and salt; stir until a soft dough forms. Turn dough out onto a floured surface. Knead until smooth and elastic (about 8 minutes); add enough of remaining flour, 1 tablespoon at a time, to prevent dough from sticking to hands (dough will feel tacky). Knead in cherries and chocolate.
4. Place dough in a large bowl coated with cooking spray, turning to coat top. Cover and let rise in a warm place (85 degrees), free from drafts, 1 hour or until doubled in size. (Gently press 2 fingers into dough. If indentation remains, dough has risen enough.)
5. Punch dough down; cover and let rest 5 minutes. Shape dough into a 9-inch round; place on a baking sheet lined with parchment paper. Lightly coat dough with cooking spray. Cover and let rise 1 hour or until doubled in size.
6. Preheat oven to 350 degrees.
7. Uncover the dough. Combine water and egg white, stirring with a whisk, and brush over dough. Sprinkle the dough with pearl sugar, if desired. Make a 1/4-inch-deep cut down the center of dough using a sharp knife.
8. Bake at 350 degrees for 30 minutes or until bread is browned on bottom and sounds hollow when tapped. Remove from pan; cool on a wire rack.
4 1/4 cups bread flour, divided
1 (12-ounce) bottle Guinness Stout
1 package dry yeast (about 2 1/4 teaspoons)
1 tablespoon granulated sugar
1 teaspoon salt
1/2 cup dried tart cherries
4 ounces bittersweet chocolate, coarsely chopped
1 teaspoon water
1 large egg white, lightly beaten
1 teaspoon pearl sugar (optional)