Preheat the oven to 350°F (175°C) and line a baking sheet with parchment paper.

In a large mixing bowl, combine 1 cup of pumpkin puree, 1 cup of sugar, ½ cup of melted vegan butter or coconut oil, and ¼ cup of plant-based milk. Stir until smooth.

In a separate bowl, sift together 2 cups of flour, 1 teaspoon of baking powder, 1 tablespoon of cinnamon, and ¼ teaspoon of salt.

Gradually add the dry mixture into the wet ingredients, stirring gently until just incorporated.

Using a tablespoon, scoop and drop rounded balls of dough onto the prepared baking sheet, spaced 2 inches apart.

Bake the cookies for about 10 minutes, or until they are lightly golden at the edges yet still soft in the center.

Remove the cookies from the oven and allow them to cool on the baking sheet for a few minutes, then transfer to a wire rack to cool completely.

In a mixing bowl, beat together 2 cups of powdered sugar, ½ cup of softened vegan butter, and 1 teaspoon of cinnamon until fluffy.

Once the cookies are cool, generously spread the cinnamon frosting over the top of each cookie.