Spray a 9 x 13 baking dish with cooking spray or grease with butter or oil.
In the bowl of a stand mixer, add the warm buttermilk, melted butter, yeast, sugar, and egg. Give it a quick mix with a fork. Attach a dough hook attachment and add 2 cups of the flour and 1/2 teaspoon salt. Mix on low until the flour is all mixed in. Add an additional 1/4-1/2 cup of flour at a time until the dough forms a ball that is still sticky but not so sticky you wouldn’t be able to handle it. Knead for at least 4-5 minutes. You will use about 3 1/2 to 4 cups of flour. Try not to over flour the dough or your rolls will be dense and not soft. *see note
Tip the dough onto a lightly floured surface and cut the rolls into 12 equal-sized pieces. Flour your hands and roll each dough piece into a round ball. Place the rolls in a grid in the baking dish 3 wide on the short sides and 4 down on the long side.
Cover with plastic wrap or a tea towel and let rise in a warm place for 20-30 minutes while you preheat the oven to 400 F. The rolls will be visibly poofy but not doubled in size.
Remove cover and bake for 15-19 minutes until the tops are light golden brown. Remove from the oven and brush with melted butter and a sprinkle of flaky salt, if desired.
Notes
Recipe Notes and Tips
*The amount of flour you need will depend on the humidity, weather, and temperature of your kitchen. Add flour until the dough is just slightly sticky.
If you use unsalted butter, add an additional ¼ teaspoon salt to the recipe.
Because these rolls don’t have a second rise, I do not recommend using active dry yeast.
If you only have active dry yeast, you can still use it — just dissolve it in the warm buttermilk (100–110°F / 38–43°C) first, and expect the dough to take about 15–20 minutes longer to rise.
Having the rolls rise in a warm place (like on top of the stovetop or next to the oven) is ideal for these quick rolls. If your home is cold you should let them rise about 10 minutes longer.
If you don't have a stand mixer, you can mix all the ingredients in a large mixing bowl with a wooden spoon and then knead in the flour by hand.
How to Store
Let rolls completely cool to room temperature before storing in an airtight container for up to 3 days.
Freeze completely cooled rolls in a freezer bag for up to 3 months.