Focaccia with grapes and walnuts

Ingredients:

• 14 g dry active yeast (1.5 tbsp)
• 3/4 cup olive oil
• 1/4 cup and 1 tbsp turbinado sugar
• 1 tbsp and 3/4 tsp coarse salt
• 2 1/4 cups premium wheat flour
• 2 1/4 tbsp. high-gluten bread flour (12.5-14 g protein)
• 120g cold unsalted butter, cut into 12 pieces
• 2 cups (approximately 450 g) seedless black grapes
• 2/3 cup raisins
• 1 cup walnuts, coarsely chopped
• 1 tsp coriander seeds, coarsely crushed
• 1 teaspoon chopped fresh rosemary
• 1/2 tsp freshly ground pepper

Preparation:

1. Attach the dough hook to the mixer. Pour 1 3/4 cups lukewarm water (104-110°F) into the mixer bowl, add the yeast, 1/2 cup olive oil, and 1 tablespoon each of sugar and salt. Turn the mixer to medium speed and mix the mixture until the yeast and sugar dissolve, then let it sit for 10 minutes, until foamy. Add both types of flour and knead the dough at medium speed for 4 minutes; the dough will still stick to the bowl and the dough hook.
2. Place small pieces of butter into the surface of the dough, spacing them slightly apart. (Do not stir.) Cover the dough with plastic wrap and let it rise in a warm place for 45-60 minutes, until the dough has doubled in size.
3. Mix the dough in a mixer with a dough hook on low speed for 1 minute, until streaks of butter no longer appear on the surface. Place the grapes and raisins in a heat-resistant bowl, microwave, and cook for 10 minutes, until the juices are released. Let cool, then strain through a sieve, discarding the liquid.
4. Grease a baking sheet with 2 tablespoons of olive oil. Divide the dough in half and place one piece on the prepared baking sheet, leaving the other piece in the bowl. Cover both pieces of dough with parchment paper and let them rise at room temperature for 30 minutes, until the dough has risen. Meanwhile, place a baking stone or an inverted baking sheet in the bottom of the oven and preheat to 230°C.
5. Using your hands, spread the dough over the entire surface of the baking sheet. Spread half of the grape mixture on top. Place the remaining dough on top and stretch it over the entire surface, pressing it together. Sprinkle with walnuts and the remaining grape mixture, pressing it into the surface of the dough. Cover loosely with parchment paper and let rise for 35-40 minutes.
6. Combine the remaining 1/4 cup sugar with the coriander, rosemary, 3/4 teaspoon salt, and pepper; sprinkle over the dough. Place the baking sheet on the hot stone and bake for 10 minutes. Reduce the temperature to 405°F (205°C) and continue baking the focaccia until the surface springs back when pressed, another 20 to 30 minutes, or until golden brown. Brush with the remaining olive oil and cool completely.
7. Store focaccia wrapped in foil in the freezer for up to 1 week.