I start by preheating my oven to 450°F, since a hot oven is key to getting that nice golden top. Then I generously grease my baking sheet with cooking spray so nothing sticks later. Using a slightly smaller pan gives you taller, fluffier pancakes if that's what you prefer.
In one bowl, I whisk together the milk, egg, pumpkin puree, sugar, melted butter, and vanilla extract until it's completely smooth. I make sure the butter isn't too hot, or it can scramble the egg slightly. This mixture should look creamy and pale orange.
In a separate bowl, I whisk the flour, baking powder, baking soda, pumpkin pie spice, and salt together. Whisking the dry ingredients first helps distribute the leavening agents evenly throughout the flour. This step only takes about a minute but makes a real difference in the final texture.
I add the dry mixture into the wet ingredients and fold gently with a rubber spatula. I stop as soon as I no longer see streaks of flour, since overmixing leads to dense, tough pancakes. A few small lumps in the batter are totally fine.
Next, I pour the batter onto my prepared sheet pan and spread it into an even layer using my spatula. I scatter the chopped pecans evenly across the top for a bit of crunch in every bite. You can leave this step out if you'd rather keep things nut-free.
I slide the pan into the oven and bake for 18 to 20 minutes, until the top turns golden and a toothpick comes out clean. The edges should pull away slightly from the sides of the pan when it's done. I always rotate the pan halfway through for even baking.
Once it's out of the oven, I let the pan cool for a few minutes before slicing it into squares or rectangles. This little rest helps the pancakes set so they hold their shape when you cut them. Serve warm with a generous drizzle of maple syrup.