Preheat the oven to 425℉. Line 2 large baking sheets with parchment paper.
In a large mixing bowl, whisk together the flour, brown sugar, baking powder, baking soda, salt, and cinnamon. Using a pastry cutter, work in the cold cubes of butter until the pieces of butter are the size of peas.
3 cups all-purpose flour, 2 tablespoons brown sugar, 4 teaspoons baking powder, ½ teaspoon baking soda, ½ teaspoon salt, 1 teaspoon ground cinnamon, ¾ cup salted butter
In a separate bowl, whisk together the pumpkin puree, milk, and egg until fully incorporated. Add to the flour/butter mixture and mix until a dough begins to form.
1 cup pumpkin puree, ½ cup milk, 1 egg
Turn the mixture onto the countertop and gently knead and fold the dough to laminate and bring the dough together. Sprinkle flour on the countertop and use a rolling pin to roll out the dough into a rectangle about 15"x12".
Cut the dough into 18 rectangular or square-shaped biscuits and arrange on the prepared baking sheets, leaving room between each biscuit.
Bake in the preheated oven for 10-12 minutes or until the tops are golden-brown and the biscuits have risen. Let cool for about 5 minutes before serving while still warm.
Notes
If you absolutely do not want any cinnamon flavor, feel free to omit the cinnamon.
Add an additional ¼ teaspoon of salt if using unsalted butter.
While biscuits are best fresh the day they are made, you can store any leftover biscuits in an airtight container or Ziplock bag at room temperature for up to 4 days. Warm leftover biscuits up before serving, if desired.