Preheat oven to 325°F (165°C). Line a baking sheet with parchment paper.
Make the dough: In a medium bowl, whisk together flour, baking powder, and salt.
Add Cool Whip and melted butter. Stir gently with a spatula until soft and dough-like.
If desired, add powdered sugar and vanilla for a sweeter cookie.
Check the texture: The dough should be soft and slightly sticky — like biscuit dough.
If it’s too crumbly, add ½ tablespoon more melted butter or milk until it holds together easily.
Shape: Drop rounded tablespoons of dough onto the baking sheet, spacing 2 inches apart.
For a smoother top, flatten gently with the back of a spoon dipped in sugar.
Bake: Bake 12–13 minutes, or until the bottoms are lightly golden.
The tops should stay pale and soft — that’s how you know they’re perfect.
Cool: Let cookies rest on the pan for 5 minutes before transferring to a rack.
They’ll firm up slightly as they cool but stay pillowy soft inside.
Glaze: In a small bowl, whisk together powdered sugar, milk, and vanilla until smooth.
Drizzle lightly over cooled cookies. Let set 10–15 minutes before serving.