Preheat your oven to 350°F (175°C). Line two baking trays with parchment paper. This prevents the cookies from sticking and helps them bake evenly.
In a medium bowl, whisk together the flour, baking powder, baking soda, cinnamon, ginger, nutmeg, cloves, and salt. Set the bowl aside while preparing the wet ingredients.
In a large mixing bowl, beat the softened butter, brown sugar, and granulated sugar until creamy and well combined. This usually takes about 2–3 minutes with an electric mixer.
Mix in the egg yolk, pumpkin puree, and vanilla extract until the mixture is smooth. The egg yolk helps provide structure, while the pumpkin adds moisture and flavor.
Gradually add the dry ingredients to the wet mixture. Stir until a soft dough forms and no visible dry flour remains. Avoid overmixing, as this can make the cookies tougher.
Refrigerate the dough for 20–30 minutes if it feels sticky or soft. Chilling helps control spreading and makes the dough easier to portion. Pumpkin puree contains considerable moisture, so this step can be particularly helpful.
In a small bowl, mix the granulated sugar and cinnamon for the optional coating. Scoop the dough into approximately 1-tablespoon portions and roll each into a ball. Roll the balls in cinnamon sugar if desired, then arrange them on the prepared trays, leaving about 2 inches between cookies.
Bake for 10–14 minutes, depending on their size. The edges should look set while the centers remain slightly soft. Avoid waiting until the cookies are completely firm in the oven, as they will continue to set while cooling.
Let the cookies rest on the baking tray for 5 minutes before transferring them to a wire rack. Allow them to cool completely for the best texture.
Whisk the powdered sugar, milk, and vanilla extract in a small bowl until smooth. Drizzle lightly over the cooled cookies. Allow the glaze to set before storing or serving.