Prepare your workspace. Preheat your oven to 350°F (175°C) and line two baking sheets with parchment paper. This prevents sticking and makes cleanup easier.
Mix the dry ingredients. In a medium bowl, whisk together flour, baking powder, baking soda, salt, pumpkin pie spice, and extra cinnamon until well combined and no lumps remain.
Cream the butter and sugars. In a large bowl, use an electric mixer to beat the vegan butter, brown sugar, and granulated sugar for 2-3 minutes until light and fluffy. Don’t rush this step—proper creaming creates the perfect cookie texture.
Add the wet ingredients. Mix in the pumpkin puree, vanilla extract, and cornstarch mixture to the butter-sugar mixture. Beat until completely incorporated, stopping to scrape down the sides of the bowl as needed.
Combine wet and dry mixtures. Add the dry ingredients to the wet ingredients in two batches, mixing on low speed just until combined. Avoid overmixing, which can make the cookies tough.
Fold in chips. If using, gently fold in the vegan white chocolate chips with a spatula until evenly distributed throughout the dough.
Chill the dough. Cover the bowl with plastic wrap and refrigerate for at least 30 minutes. This helps prevent spreading and intensifies the flavors.
Form the cookies. Using a cookie scoop, form 1.5-inch balls of dough and roll them in turbinado sugar for a sparkly, crunchy exterior.
Bake to perfection. Place the cookies on the prepared baking sheets about 2 inches apart and bake for 12-14 minutes, until the edges are set but the centers still look slightly soft.
Cool properly. Allow the cookies to cool on the baking sheets for 5 minutes before transferring to a wire rack to cool completely. They’ll continue to firm up as they cool.