ingredients

for the dough:

• 100g sourdough starter, fed and active

• 240g water

• 200g apple juice

• 4 cups all-purpose flour (or bread flour)

• 1 tsp kosher salt

• 2 tbsp cinnamon

• olive oil

for the apple filling:

• 3-4 apples, diced or grated

• 1/4 cup cinnamon sugar (you can make your own mixing a 1:4 ratio of cinnamon to sugar)

• 1 tbsp all-purpose flour

for the glaze:

• 2 cups powdered sugar

• 1/4 cup milk

• 1 tsp vanilla extract

steps

1. In a large mixing bowl, add the starter, water, apple juice, sugar, salt, and cinnamon. Mix until dispersed.

2. Add in the flour and mix with a spatula until no flour clumps remain. Cover with plastic wrap and let sit 10 minutes.

3. Prepare the apple filling. Dice 3-4 apples and put into a container with a cover (I used a deli cup). Add in 1 tbsp cinnamon sugar and the flour. Cover and shake to coat the apple pieces well. Optionally, you can cook this in a medium pan to reduce liquid and thicken into something similar to apple pie filling to make things easier later. Refrigerate.

4. Perform 2-3 sets of fold and turns until the dough stretches a bit more easily without tearing. Cover and let rest for 30 minutes. 

5. Perform 1 set of fold and turns every 30 minutes for the next 2 hours (4 sets total). After the last set, cover and let rise for 1-2 hours until doubled or almost double.

6. Prepare a 9x13" baking pan by drizzling some olive oil to coat the pan.

7. Turn the dough out into the baking pan. Drizzle some more olive oil on top of dough.

8. Using your hands (get some olive oil on them to prevent sticking), spread the dough out to roughly stretch it into the shape of the pan.

9. Sprinkle half of the cinnamon sugar and all of the apple filling to coat the top. Roll the dough from one side to the other. It's okay if some of it dough tears - just try to envelop the filling as best as possible. Rotate the dough so its long edge is aligned with the long edge of the pan. You can repeat the roll if you'd like to spread out the filling a bit more. Use your hands to gently press this out to roughly fit the pan again. Cover and either let rise at room temperature for another 2-4 hours until doubled, or place in fridge to let it slowly rise overnight.

10. Preheat oven to 425F.

11. Rub some olive oil onto your fingers. Dimple the focaccia all over. Sprinkle the remaining half of the cinnamon sugar on top. Bake for 25 minutes until golden brown.

12. 5 minutes before baking is done, prepare the glaze. Whisk together the powdered sugar, milk, and vanilla extract (optional: add some cinnamon). Immediately when the focaccia comes out of the oven, pour the glaze over the top while it's still hot.

13. Let cool ~20-30 minutes until the glaze has hardened and set before cutting. Enjoy!