2/3 cup whole milk
5 tablespoons sugar, divided
1 3/4 teaspoons active dry yeast (from one 1/4-ounce envelope)
2 large eggs, room temperature (see egg replacement page)
2 3/4 cups gluten-free all-purpose flour
1 teaspoon kosher salt
1/2 cup(1 stick) unsalted butter, cut into 1-inch pieces, room temperature, plus 1/2 tablespoon, melted
Stand Mixer Method
Heat milk in a small saucepan over medium heat or in a microwave until an instant-read thermometer registers 110°–115°. Transfer milk to a 2-cup measuring cup; stir in 1 Tbsp. sugar. Sprinkle yeast over milk and whisk to blend. Let sit until yeast is foamy, about 5 minutes. Add eggs; whisk until smooth.
Combine remaining 4 Tbsp. sugar, flour, and salt in the bowl of a stand mixer fitted with a dough hook. Add milk mixture. With mixer running, add 1/2 cup room-temperature butter, 1 piece at a time, blending well between additions. Mix on medium speed for 1 minute. Knead on medium-high speed until dough is soft and silky, about 5 minutes.
Brush a medium bowl with some melted butter; place dough in bowl. Brush top of dough with remaining melted butter; cover with plastic wrap. DO AHEAD: Can be made 1 day ahead. Cover with plastic; chill.
Let dough rise in a warm, draft-free area until doubled in size, 1–1 1/2 hours (or 2–2 1/2 hours if dough has been refrigerated).