Yield: One 9 x 13 sheet tray
3 cups seltzer water
2 ½ tablespoons active dry yeast
4 ½ tablespoons granulated sugar
¾ cup mayonnaise
¾ cup mascarpone cheese
4 large eggs
3 ½ cups Cup4Cup Multipurpose Flour
3 cups Cup4Cup Wholesome Flour
3 tablespoons kosher salt
1 tablespoon baking powder
1 teaspoon baking soda
Olive oil, for finishing
Maldon salt or other coarse salt, for finishing
Fresh rosemary sprigs, for finishing
- Combine the seltzer, yeast and sugar in a bowl, and stir gently to combine. Do not over mix to keep the bubbles immersed. The bubbles will give the focaccia its light and airy texture.
- In a separate bowl, combine the mayonnaise, mascarpone, and eggs, stirring to incorporate well.
- Add the mayonnaise combination to the yeast mixture and very gently stir to combine, using a wooden spoon. Again, do not over mix to keep the bubbles intact.
- Whisk together both flours, salt, baking powder, and baking soda in a separate bowl. Very slowly add the flour mixture to the wet ingredients, stirring until the dough comes together.
- Spread a generous amount of olive oil into a 9×13 inch sheet tray. Spread the dough into the sheet tray using your hands, gently pressing it into shape. Top the dough with more olive oil and let proof at room temperature for 1 ½ hours.
- Preheat the oven to 350°F.
- Before baking, top the focaccia with chopped rosemary and a generous amount of Maldon salt. Bake for 25 minutes or until golden brown.