Preheat your oven to 425°F (218°C). Allow at least 10 minutes for it to fully reach temperature — this high heat is essential for getting domed tops. Line a standard 12-cup muffin pan with paper liners and lightly grease the inside of each liner with cooking spray.
In a large bowl, add 1¾ cups (219g) all-purpose flour, 1 tsp baking soda, 1 tsp baking powder, 1½ tsp ground cinnamon, 1½ tsp pumpkin pie spice, ¼ tsp ground ginger, ¼ tsp ground nutmeg, and ½ tsp salt. Whisk together for about 1 minute until the mixture is uniform in color with no visible clumps. Set aside.Checkpoint: You are ready to move on when the dry mix looks evenly blended with no streaks of individual spices.
In a medium bowl, add ½ cup (120ml) vegetable oil, ½ cup (100g) granulated sugar, ½ cup (100g) packed brown sugar, 2 large room-temperature eggs, 1¼ cups (284g) canned pumpkin puree, ⅓ cup (80ml) milk, and 1 tsp vanilla extract. Whisk together for 1–2 minutes until the mixture is smooth, glossy, and deep orange with no sugar lumps remaining.Checkpoint: You are ready to move on when the wet mixture looks completely smooth and well combined.
Pour the wet ingredient bowl into the large bowl of dry ingredients. Using a rubber spatula, fold the two together gently. Count your strokes — stop the moment you no longer see any dry flour streaks. This should take about 30–45 seconds. The batter will be thick, lumpy, and orange. A few small lumps are completely normal and correct. Do NOT keep stirring to smooth it out.
Spoon or scoop the batter evenly into the 12 prepared muffin cups. Fill each cup all the way to the top — the batter should mound slightly above the rim of the liner. This is what creates bakery-style tall, domed tops.Checkpoint: You are ready to move on when all 12 cups are filled to the top and the batter looks evenly distributed.
Place the muffin pan on the center rack of your preheated 425°F (218°C) oven. Bake for exactly 5 minutes at this high temperature. Do NOT open the oven door during this time.
Without opening the oven door, reduce the oven temperature to 350°F (177°C). Continue baking for 16–18 more minutes (21–23 minutes total). At the end of this time, insert a toothpick into the center of a muffin. It should come out clean with no wet batter — a few dry crumbs are fine. The tops should be golden-brown and domed.Checkpoint: You are ready to move on when the toothpick comes out clean and the tops look golden and set.
Remove the pan from the oven and let the muffins cool in the pan for exactly 5 minutes. Then carefully lift each muffin out and transfer to a wire rack to finish cooling for at least 10 more minutes. Cooling on the rack prevents gummy, steamy bottoms.