In a large bowl, combine 1¾ cups (420 grams) of room temperature water and 2 tablespoons (28 grams) of olive oil. Make sure the water is warm enough to activate the instant yeast. Then, add 4¼ cups (540 grams) of bread flour, 3½ teaspoons (10.5 grams) of kosher salt, 1 tablespoon (12 grams) of granulated sugar, and the whole package of instant yeast. Stir everything together using a rubber spatula or a wooden spoon until a cohesive dough forms. Don’t worry if it’s a bit shaggy and tacky; that’s a good sign!
Cover the bowl with a clean kitchen towel and let the dough rise in a warm, draft-free place (around 75°F/24°C) for 1½ hours. Every 30 minutes, gently fold the dough in the bowl to help develop the gluten structure. To fold, wet your hands, reach under one side of the dough, gently stretch it up, and fold it over the center. Repeat this process on all sides.
While the dough is rising, prepare a 13x9-inch baking pan by lining it with parchment paper. Let the excess extend over the sides for easy removal later. Brush the remaining 2 tablespoons (28 grams) of olive oil onto the parchment. This will help prevent sticking and add flavor.
Once the dough has risen, turn it out into the prepared pan. Using just your fingertips, gently stretch the dough to form a rectangle about 10x8 inches. If the dough feels tight and resists stretching, let it rest for 5 to 10 minutes and then try again.
In a small bowl, combine ¾ cup (73 grams) of light brown sugar and 2 tablespoons (12 grams) of ground cinnamon. Sprinkle half of this mixture (about ¼ cup or 43 grams) evenly over the dough, ensuring even coverage.
Starting at one short side, carefully roll the dough up into a log. Place it lengthwise in the pan, seam side down. Allow it to stand for 10 minutes. Then, using your fingertips, gently stretch the dough to fill the pan completely.
Cover the pan and let the dough rise in a warm, draft-free location until it has doubled in size and appears jiggly—this should take about 45 minutes to 1 hour.
Preheat your oven to 425°F (220°C) while the dough is rising. Once risen, dimple the dough using your fingertips, pressing down gently without tearing.
In a small bowl, combine the melted butter with the remaining brown sugar mixture. Whisk until well combined. Spoon this mixture evenly over the dough.
Bake in the preheated oven for 15 to 20 minutes or until the focaccia is golden brown. An instant-read thermometer inserted into the center should register 190°F (88°C). Allow it to cool in the pan for 10 minutes.
Using the excess parchment as handles, carefully remove the focaccia from the pan. In another bowl, whisk together 2 ounces (57 grams) of cream cheese and ⅓ cup (40 grams) of confectioners’ sugar. Whisk in 2 tablespoons (30 grams) of whole milk until smooth, then drizzle this over the warm focaccia. Serve warm and enjoy the delightful flavors!