Preheat the oven to 425°F (220°C). Position a rack in the center of the oven. Line a standard 12-cup muffin pan with paper liners. Make sure the oven is fully preheated before adding the batter, since the initial high heat helps create a stronger rise.

In a medium bowl, whisk together the all-purpose flour, baking powder, baking soda, cinnamon, ginger, nutmeg, and salt. Mix until the spices and leavening agents are evenly distributed. The flour mixture should have a uniform pale beige color without visible pockets of cinnamon or baking powder.

In a separate large bowl, combine the pumpkin puree, eggs, vegetable oil, light brown sugar, granulated sugar, and vanilla extract. Whisk for about 1 minute, or until the mixture looks smooth, glossy, and evenly orange. Break up any brown sugar lumps so they do not remain in the finished muffins.

Add the dry ingredients to the pumpkin mixture: Using a silicone spatula, gently fold until the flour is just incorporated. The batter should be thick, soft, and scoopable rather than runny. A few small lumps are normal. Stop mixing once no dry flour remains. If the batter looks slightly uneven, resist the temptation to keep stirring; excessive mixing can make the muffins tough.

Add 3/4 cup (about 128 g) of the semi-sweet chocolate chips to the batter. Fold gently a few times until the chips are distributed throughout. Reserve the remaining 1/4 cup (about 42 g) for the muffin tops. The batter should hold its shape briefly when lifted with a spoon.

Divide the batter evenly among the 12 prepared muffin cups, filling each approximately three-quarters to nearly full, depending on the depth of the pan. Scatter the reserved chocolate chips over the tops, pressing them very lightly into the surface so they stay in place as the muffins rise.

Place the muffin pan on the center rack and bake at 425°F (220°C) for 5 minutes. Without opening the oven door, reduce the temperature to 350°F (175°C). Continue baking for approximately 15–19 minutes, for a total baking time of 20–24 minutes. The muffins are ready when their tops are raised and set, the edges are lightly golden, and a toothpick inserted into the center of a muffin comes out clean or with a few moist crumbs. Avoid inserting the toothpick directly into a chocolate chip, which can make the center appear underbaked. If wet batter remains on the toothpick, bake for another 2 minutes and check again.

Let the muffins cool in the pan for 5 minutes. Carefully transfer them to a wire rack and allow them to cool for another 15 minutes before serving. The crumb continues to settle as the muffins cool. Moving them out of the pan prevents steam from collecting underneath and making the liners soggy.