Prepare Dough: In a small bowl, dissolve the yeast in half of the warm water and let it sit for about 5 minutes until it’s foamy. In a large bowl, mix sliced butter, sugar, and salt with the remaining warm water. Add the egg yolk and the yeast mixture, then stir in the flour until everything is combined.
Rest Dough: Brush a 9×13 baking dish with 2 tablespoons of melted butter. Spread the dough evenly in the dish, cover it with plastic wrap, and let it rest for 15 minutes. Preheat your oven to 350°F.
Add Toppings & Bake: Remove the plastic wrap, brush the dough with the remaining butter, and sprinkle mozzarella, parmesan, garlic salt, and oregano on top. Bake for 28-31 minutes until golden brown and bubbly. Allow it to cool for approximately 10 minutes, then cut into 8 pieces and serve with marinara.