Preheat your oven to 180°C (350°F) and line baking sheets with parchment paper to ensure easy removal.
In a large mixing bowl, whisk together the flour, baking soda, salt, and cinnamon until evenly combined. This creates a flavorful dry base for the cookies.
In another bowl, beat the softened butter and brown sugar together using an electric mixer or whisk until the mixture is fluffy, light, and slightly pale—about 2-3 minutes. The sound should be a gentle whir, and the mixture will look creamy.
Mix in the canned pumpkin and vanilla extract to the butter-sugar mixture until well incorporated, creating a thick, moist batter with a warm aroma of spices.
Gradually add the dry ingredients to the wet mixture, folding gently until just combined—avoid overmixing to keep the cookies tender and soft.
Using a cookie scoop or two spoons, portion the dough onto the prepared baking sheets, spacing each about 2 inches apart to allow for spreading. The dough should look like rounded mounds.
Bake in the preheated oven for 12-15 minutes, or until the edges turn a light golden brown and the tops are set but still slightly soft. You’ll hear a gentle sizzle as they bake.
Remove the baking sheets from the oven and let the cookies cool on a wire rack for at least 30 minutes until completely cooled and firm enough to handle.
While the cookies cool, prepare the filling by beating the softened cream cheese and powdered sugar together until smooth and creamy, about 2 minutes. The filling should be fluffy and spreadable.
Once the cookies are cooled, spread a generous layer of the cream cheese filling on the flat side of one cookie, then top with a second cookie to create a sandwich. Gently press together to secure.
Repeat with the remaining cookies and filling. For best flavor, chill the assembled whoopie pies for at least 30 minutes before serving, allowing the flavors to meld and the filling to set.
