In a large mixing bowl, combine pumpkin puree, brown sugar, and melted vegan butter until smooth. Gradually mix in all-purpose flour, baking soda, and cinnamon until just blended.

Drop generous balls of dough onto a parchment-lined baking sheet, leaving about 2 inches between each cookie. Flatten each ball slightly with the back of the spoon.

Preheat your oven to 350°F (175°C) and bake cookies for about 10 minutes until the edges are golden and centers are soft. Let cool on the baking sheet for a few minutes before transferring to a wire rack.

Prepare the frosting by whipping together softened vegan butter, powdered sugar, and cinnamon until fluffy and smooth. Frost cooled cookies with the cinnamon frosting.

Serve fresh alongside a warm mug of cider, or store in an airtight container.