Step 1

Preheat oven to 425°. Toss peaches and 2 Tbsp. sugar in a large bowl; let sit, tossing occasionally, until they release some of their juices, 20–30 minutes.

Step 2

Meanwhile, scatter remaining ⅓ cup sugar evenly across a heavy 8” skillet, preferably cast iron. Cook over medium heat, stirring occasionally, until sugar is melted and starting to caramelize (it should be pale amber at this point), about 5 minutes. Continue to cook, without stirring, until caramel is a deep amber color, about another 5 minutes.

Step 3

Remove skillet from heat; mix in butter, then gradually add bourbon, stirring constantly. Caramel will seize initially but smooth out again later, so don’t worry. Add salt and scrape in vanilla seeds; reserve pod for another use. Set skillet over medium-low heat and stir until any hardened caramel is dissolved, about 4 minutes. Scrape peaches into skillet and cook, gently stirring occasionally, until they’ve softened and released more juices, about 5 minutes. Using a slotted spoon, transfer peaches to a medium bowl and continue to cook caramel in skillet until there is just enough to cover surface, 6–8 minutes. Return peaches to skillet and arrange skin side down; remove skillet from heat.

Step 4

Gently roll out puff pastry on a lightly floured work surface just to smooth out creases; cut out a 10” round. Drape over peaches and tuck edges into pan. (It’s okay if it doesn’t look perfect. You just want to make sure the dough is tucked in all the way around). Bake until pastry begins to puff, 20–25 minutes. Reduce heat to 350° and continue to bake until pastry is golden brown and cooked all the way through, 20–25 minutes longer. Transfer skillet to a wire rack and let tarte Tatin cool 25 minutes before inverting onto a platter.