To the bowl of a stand mixer fitted with the paddle attachment, add warm milk, 1 tablespoon of the granulated sugar, and yeast. Mix gently and let sit for about 5 minutes until foamy.
Add eggs, softened butter, remaining granulated sugar, all-purpose flour, bread flour, and kosher salt.
Switch to the dough hook attachment and mix on low speed until just combined. Then, increase speed to medium and knead for about 5 minutes, or until the dough is smooth and elastic.
Lightly spray a medium bowl with nonstick cooking spray. Transfer the dough to the bowl, turning it to coat all sides. Cover with a clean towel or plastic wrap and let rise in a warm place until doubled in size, 1–2 hours.
Lightly flour your counter or work surface. Once the dough has doubled, gently punch it down and roll it into a 10×15-inch rectangle, about ¼- inch thick.