Tall, domed, bakery-style pumpkin chocolate chip muffins with melty chips in every single bite. They stay soft and moist for days, because oil does the work butter can't. The chips never sink. And those proud, crackly tops? That's a hot-oven trick I'll walk you through. Two bowls, one spoon, no mixer.
Preheat the oven to 425°F. Line a 12-cup muffin tin with paper liners.
In a large bowl, whisk together the flour, pumpkin pie spice, baking soda, baking powder, and salt.
In another bowl, whisk the pumpkin, oil, milk, granulated sugar, brown sugar, eggs, and vanilla until smooth.
Pour the wet ingredients into the dry. Stir just until no flour streaks remain. Do not overmix.
Toss the chocolate chips with a tablespoon of flour, then fold them into the batter.
Divide the batter among the cups, filling each nearly full. Press a few reserved chips into the tops.
Bake at 425°F for 5 minutes, then, without opening the oven, reduce the heat to 350°F and bake 14 to 17 minutes more, until a toothpick comes out with only a few moist crumbs.
Cool in the pan 5 minutes, then transfer to a rack to cool completely.