Prepare your yeast mixture by combining the yeast, lukewarm water and sugar. Mix well and allow to sit in a warm place for 10 minutes. You should see that bubbles have formed on the surface of your mixture.
¾ cup lukewarm water, 2½ tsp active dry yeast, 1 tbsp sugar
In the bowl of your stand mixer fitted with the dough hook attachment combine all of your dough ingredients, including the yeast mixture. Mix on medium speed for approximately 8 - 10 minutes or until the dough is smooth and has pulled away from the sides of the mixing bowl.
3 cups all-purpose flour, 1 egg, 1 egg yolk, ⅓ cup sugar, 4 tbsp butter, unsalted, 1 tsp Kosher salt
Transfer to a large bowl that has been lightly coated with flour. Cover with plastic wrap and then a clean towel. Leave in a warm spot for at least 2 hours, or until the dough has doubled in size.
After the dough has risen, punch down the dough and then transfer it to a floured work surface. Roll the dough out until you make a rectangle that is about 13 x 18 inches.