Extra-Buttery Mashed Spuds

Place 4 pounds Yukon Gold potatoes, peeled, cut into 2" pieces, in a large pot and pour in cold water to cover by 1". Add 1 tablespoon kosher salt and bring to a boil. Reduce heat and simmer until potatoes are very tender but not saturated or crumbly, 20 –25 minutes (boiling will lead to waterlogged pieces). Drain potatoes, reserving 1/2 cup cooking liquid if making potatoes ahead. Return potatoes to pot and set over low heat. Gently stir until dry, about 1 minute. Meanwhile, heat 1 1/2 cups whole milk, 3 thyme sprigs, if desired, 2 bay leaves, and 3/4 cup (1 1/2 sticks) unsalted butter in a small saucepan over medium heat until butter is melted. Remove from heat. Pass hot potatoes through a ricer into a large bowl (if allowed to cool, the potatoes will become gummy). Remove herbs from warm milk mixture; discard. Gradually add milk mixture to potatoes, stirring vigorously with a wooden spoon until combined and smooth; season with salt and pepper. Serve mashed potatoes with a few pats of butter on top.