In the bowl of the stand mixer, whisk the warm milk and yeast together. Allow the mixture to sit for a few minutes. See notes if you do not have a stand mixer.
1 cup (240 ml) warm whole milk, 110 degrees*, 2 1/4 teaspoons (1 standard packet) active dry yeast*
With the dough hook or paddle attachment, on medium speed, mix in the sugar, 4 Tablespoons of browned butter, egg, and egg yolk, until completely combined.
1/3 cup (67 g) granulated sugar, 1 large egg + 1 large egg yolk, 1/4 cup (4 Tablespoons or 56 g) salted butter*
On low speed, add in about half of the flour. Mix until incorporated. Scrape excess flour off the sides of the bowl.
3 1/2 cups (455 g) all purpose flour
Add the remaining flour and salt. The dough should begin to come together.
1/2 teaspoon kosher salt
Knead on high speed for 5-6 minutes. The dough will look smooth and should stick to the dough hook and bottom of the bowl. It will still be sticky and hard to handle.
Use a spatula to scrape down the sides of the bowl and form the dough into a ball. Cover with a towel or plastic wrap.
Allow the dough to rise for about 45 minutes in a warm place, like near the oven or on a window sill. While the dough rises, brush a 9 x 13 baking dish generously with melted butter or spray with cooking spray or line with parchment. Set aside.